ARM: add ATAGS dependencies to non-DT platforms

There are a total of eight platforms that only suppor ATAGS based boot
with board files but no devicetree booting.

For dove, the DT support is part of the mvebu platform, which shares
driver but no code in arch/arm.

Most of these will never get converted to DT, and the majority of the
board files appear to be entirely unused already. There are still known
users on a few machines, and there may be interest in converting some
omap1, ep93xx or footbridge machines over in the future.

For the moment, just add a Kconfig dependency to hide these platforms
completely when CONFIG_ATAGS is disabled, and reorder the priority
of the options: Rather than offering to turn ATAGS off for platforms
that have DT support, make it a top-level setting that determines
which platforms are visible.

The s3c24xx platform supports one machine with DT support, but it
cannot be built without also including ATAGS support, and the
entire platform is scheduled for removal, so leaving the entire
platform behind a dependency seems good enough.

All defconfig files should keep working, as the option remains default
enabled.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/Kconfig

@@ -350,6 +350,7 @@ config ARCH_MULTIPLATFORM
 config ARCH_FOOTBRIDGE
 	bool "FootBridge"
 	depends on CPU_LITTLE_ENDIAN
+	depends on ATAGS
 	select CPU_SA110
 	select FOOTBRIDGE
 	select NEED_MACH_MEMORY_H
@@ -361,6 +362,7 @@ config ARCH_RPC
 	bool "RiscPC"
 	depends on !CC_IS_CLANG && GCC_VERSION < 90100 && GCC_VERSION >= 60000
 	depends on CPU_LITTLE_ENDIAN
+	depends on ATAGS
 	select ARCH_ACORN
 	select ARCH_MAY_HAVE_PC_FDC
 	select ARCH_SPARSEMEM_ENABLE
@@ -380,6 +382,7 @@ config ARCH_RPC
 config ARCH_SA1100
 	bool "SA1100-based"
 	depends on CPU_LITTLE_ENDIAN
+	depends on ATAGS
 	select ARCH_MTD_XIP
 	select ARCH_SPARSEMEM_ENABLE
 	select CLKSRC_MMIO
@@ -1539,7 +1542,7 @@ config USE_OF
 	  Include support for flattened device tree machine descriptions.
 
 config ATAGS
-	bool "Support for the traditional ATAGS boot data passing" if USE_OF
+	bool "Support for the traditional ATAGS boot data passing"
 	default y
 	help
 	  This is the traditional way of passing data to the kernel at boot

arch/arm/mach-cns3xxx/Kconfig

@@ -2,6 +2,7 @@
 menuconfig ARCH_CNS3XXX
 	bool "Cavium Networks CNS3XXX family"
 	depends on ARCH_MULTI_V6
+	depends on ATAGS
 	select ARM_GIC
 	help
 	  Support for Cavium Networks CNS3XXX platform.

arch/arm/mach-dove/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 menuconfig ARCH_DOVE
 	bool "Marvell Dove" if ARCH_MULTI_V7
+	depends on ATAGS
 	select CPU_PJ4
 	select GPIOLIB
 	select MVEBU_MBUS

arch/arm/mach-ep93xx/Kconfig

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 menuconfig ARCH_EP93XX
 	bool "EP93xx-based"
+	depends on ATAGS
 	depends on ARCH_MULTI_V4T
 	depends on CPU_LITTLE_ENDIAN
 	select ARCH_SPARSEMEM_ENABLE

arch/arm/mach-iop32x/Kconfig

@@ -3,6 +3,7 @@ menuconfig ARCH_IOP32X
 	bool "IOP32x-based platforms"
 	depends on ARCH_MULTI_V5
 	depends on CPU_LITTLE_ENDIAN
+	depends on ATAGS
 	select CPU_XSCALE
 	select GPIO_IOP
 	select GPIOLIB

arch/arm/mach-mv78xx0/Kconfig

@@ -3,6 +3,7 @@ menuconfig ARCH_MV78XX0
 	bool "Marvell MV78xx0"
 	depends on ARCH_MULTI_V5
 	depends on CPU_LITTLE_ENDIAN
+	depends on ATAGS
 	select CPU_FEROCEON
 	select GPIOLIB
 	select MVEBU_MBUS

arch/arm/mach-omap1/Kconfig

@@ -3,6 +3,7 @@ menuconfig ARCH_OMAP1
 	bool "TI OMAP1"
 	depends on ARCH_MULTI_V4T || ARCH_MULTI_V5
 	depends on CPU_LITTLE_ENDIAN
+	depends on ATAGS
 	select ARCH_HAS_HOLES_MEMORYMODEL
 	select ARCH_OMAP
 	select CLKSRC_MMIO

arch/arm/mach-s3c/Kconfig.s3c24xx

@@ -8,7 +8,7 @@ menuconfig ARCH_S3C24XX
 	bool "Samsung S3C24XX SoCs (deprecated, see help)"
 	depends on ARCH_MULTI_V4T || ARCH_MULTI_V5
 	depends on CPU_LITTLE_ENDIAN
-	select ATAGS
+	depends on ATAGS
 	select CLKSRC_SAMSUNG_PWM
 	select GPIO_SAMSUNG
 	select GPIOLIB