memory: change LP_SRAM to helper config

Having both LP_SRAM (bool) and LP_MEMORY_BANKS (int) is error prone.
It's better to make LP_SRAM just a helper config that is set
to true if there is any LP memory bank in use.

Signed-off-by: Janusz Jankowski <janusz.jankowski@linux.intel.com>

Kconfig

@@ -19,18 +19,17 @@ config HP_MEMORY_BANKS
 
 config LP_MEMORY_BANKS
 	int "LP memory banks count"
-	default 1
-	depends on LP_SRAM
+	default 0
 	help
-	  Available memory banks count for Low Power memory
+	  Available memory banks count for Low Power memory.
+	  It can be used to turn ON/OFF LPSRAM bank/s.
+	  Firmware will turn on only as many banks as are defined here.
 
 config LP_SRAM
-	bool "Enable LPSRAM memory"
-	default n
+	bool
+	default LP_MEMORY_BANKS > 0
 	help
-	  Turn ON/OFF LPSRAM bank/s. This provides an option to enable an LPSRAM
-	  memory for specific platform. Until this options is enabled firmware will
-	  not enable any of LPSRAM memory banks.
+	  Indicates that platform uses LPSRAM.
 
 config CAVS_LPS
 	bool "Intel cAVS Low Power Sequencer for Power Management"

src/arch/xtensa/configs/apollolake_defconfig

@@ -3,4 +3,3 @@ CONFIG_CAVS_DMIC=y
 CONFIG_CAVS_SSP=y
 CONFIG_LP_MEMORY_BANKS=2
 CONFIG_HP_MEMORY_BANKS=8
-CONFIG_LP_SRAM=y

src/arch/xtensa/configs/cannonlake_defconfig

@@ -7,5 +7,4 @@ CONFIG_CAVS_LPRO=y
 CONFIG_CORE_COUNT=4
 CONFIG_LP_MEMORY_BANKS=1
 CONFIG_HP_MEMORY_BANKS=47
-CONFIG_LP_SRAM=y
 CONFIG_PERFORMANCE_COUNTERS=y

src/arch/xtensa/configs/cannonlake_gcc_defconfig

@@ -6,4 +6,3 @@ CONFIG_CAVS_LPS=y
 CONFIG_CORE_COUNT=4
 CONFIG_LP_MEMORY_BANKS=1
 CONFIG_HP_MEMORY_BANKS=47
-CONFIG_LP_SRAM=y