Add option to indicatet that data is retained in SDRAM

arch/Kconfig

@@ -139,6 +139,11 @@ config ARCH_HAVE_VFORK
 
 config ARCH_HAVE_MMU
 	bool
+	default n
+
+config ARCH_NAND_HWECC
+	bool
+	default n
 
 config ARCH_IRQPRIO
 	bool "Prioritized interrupt support"
@@ -428,4 +433,19 @@ config FLASH_SIZE
 		refers to the FLASH that you link program code into.
 
 endif # BOOT_RUNFROMFLASH && ARCH_HAVE_MMU
+
+config ARCH_HAVE_SDRAM
+	bool
+	default n
+
+config BOOT_SDRAM_DATA
+	bool "Data in SDRAM"
+	default n
+	depends on ARCH_HAVE_SDRAM
+	---help---
+		This selection should be set if data lies in SDRAM (vs. SRAM).  In
+		that case, the initialization sequence is a little different:  SDRAM
+		must be configured before before the .data and .bss sections can be
+		initialized.
+
 endmenu # Boot Memory Configuration

arch/arm/Kconfig

@@ -16,6 +16,7 @@ config ARCH_CHIP_A1X
 	select ARCH_HAVE_FPU
 	select ARCH_HAVE_MMU
 	select ARCH_HAVE_LOWVECTORS
+	select ARCH_HAVE_SDRAM
 	select BOOT_RUNFROMSDRAM
 	---help---
 		Allwinner A1X family: A10, A10S (A12), A13 (ARM Cortex-A8)

arch/arm/src/lpc17xx/Kconfig

@@ -374,6 +374,7 @@ config LPC17_EXTDRAM
 	bool "Configure external DRAM"
 	default n
 	depends on ARCH_HAVE_EXTDRAM
+	select ARCH_HAVE_SDRAM
 	---help---
 		Configure external DRAM memory and, if applicable, map then external
 		DRAM into the memory map.

arch/arm/src/lpc31xx/Kconfig

@@ -104,6 +104,7 @@ config LPC31_EXTDRAM
 	bool "Configure external DRAM"
 	default n
 	depends on ARCH_HAVE_EXTDRAM
+	select ARCH_HAVE_SDRAM
 	---help---
 		Configure external DRAM memory and, if applicable, map then external
 		DRAM into the memory map.

arch/arm/src/sam34/Kconfig

@@ -720,6 +720,7 @@ config SAM34_EXTDRAM
 	bool "Configure external DRAM"
 	default n
 	depends on ARCH_HAVE_EXTDRAM
+	select ARCH_HAVE_SDRAM
 	---help---
 		Configure external DRAM memory and, if applicable, map then external
 		DRAM into the memory map.