can: remove obsolete PCH CAN driver

The PCH CAN driver is a driver for a Bosch C_CAN controller IP core which
is attached to the system via PCI. This code has been introduced in 2011
by Oki Semiconductors developers to support the Intel Atom E6xx series
I/O Hub (aka EG20T IOH PCH CAN). Since 2012 the driver only has been
maintained by the kernel community.

As there is a well maintained and continously tested C_CAN/D_CAN driver
which also supports the PCI configuration from the PCH CAN EG20T setup
this driver became obsolete.

Cc: Jacob Kroon <jacob.kroon@gmail.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Dario Binacchi <dariobin@libero.it>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220924174424.86541-1-socketcan@hartkopp.net
Acked-by: Jacob Kroon <jacob.kroon@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/Kconfig

@@ -198,14 +198,6 @@ config CAN_XILINXCAN
 	  Xilinx CAN driver. This driver supports both soft AXI CAN IP and
 	  Zynq CANPS IP.
 
-config PCH_CAN
-	tristate "Intel EG20T PCH CAN controller"
-	depends on PCI && (X86_32 || COMPILE_TEST)
-	help
-	  This driver is for PCH CAN of Topcliff (Intel EG20T PCH) which
-	  is an IOH for x86 embedded processor (Intel Atom E6xx series).
-	  This driver can access CAN bus.
-
 source "drivers/net/can/c_can/Kconfig"
 source "drivers/net/can/cc770/Kconfig"
 source "drivers/net/can/ctucanfd/Kconfig"

drivers/net/can/Makefile

@@ -30,6 +30,5 @@ obj-$(CONFIG_CAN_SJA1000)	+= sja1000/
 obj-$(CONFIG_CAN_SUN4I)		+= sun4i_can.o
 obj-$(CONFIG_CAN_TI_HECC)	+= ti_hecc.o
 obj-$(CONFIG_CAN_XILINXCAN)	+= xilinx_can.o
-obj-$(CONFIG_PCH_CAN)		+= pch_can.o
 
 subdir-ccflags-$(CONFIG_CAN_DEBUG_DEVICES) += -DDEBUG

drivers/net/can/c_can/Kconfig

@@ -20,5 +20,6 @@ config CAN_C_CAN_PCI
 	depends on PCI
 	help
 	  This driver adds support for the C_CAN/D_CAN chips connected
-	  to the PCI bus.
+	  to the PCI bus. E.g. for the C_CAN controller IP inside the
+	  Intel Atom E6xx series IOH (aka EG20T 'PCH CAN').
 endif