mx31pdk: Convert CONFIG_MX31 flag to use Kconfig.

Move CONFIG_MX31 from mx31pdk.h to mx31pdk_defconfig and introduce
necessary Kconfig changes as well.

Signed-off-by: Magnus Lilja <lilja.magnus@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/arm/Kconfig

@@ -497,13 +497,6 @@ config TARGET_X600
 	select SUPPORT_SPL
 	select PL011_SERIAL
 
-config TARGET_MX31PDK
-	bool "Support mx31pdk"
-	select BOARD_LATE_INIT
-	select CPU_ARM1136
-	select SUPPORT_SPL
-	select BOARD_EARLY_INIT_F
-
 config TARGET_WOODBURN
 	bool "Support woodburn"
 	select CPU_ARM1136
@@ -665,6 +658,10 @@ config ARCH_MX28
 	select PL011_SERIAL
 	select SUPPORT_SPL
 
+config ARCH_MX31
+	bool "NXP i.MX31 family"
+	select CPU_ARM1136
+
 config ARCH_MX7ULP
         bool "NXP MX7ULP"
 	select CPU_V7A
@@ -1305,6 +1302,8 @@ source "arch/arm/cpu/armv7/ls102xa/Kconfig"
 
 source "arch/arm/mach-imx/mx2/Kconfig"
 
+source "arch/arm/mach-imx/mx3/Kconfig"
+
 source "arch/arm/mach-imx/mx5/Kconfig"
 
 source "arch/arm/mach-imx/mx6/Kconfig"
@@ -1392,7 +1391,6 @@ source "board/freescale/ls1046ardb/Kconfig"
 source "board/freescale/ls1012aqds/Kconfig"
 source "board/freescale/ls1012ardb/Kconfig"
 source "board/freescale/ls1012afrdm/Kconfig"
-source "board/freescale/mx31pdk/Kconfig"
 source "board/freescale/mx35pdk/Kconfig"
 source "board/freescale/s32v234evb/Kconfig"
 source "board/gdsys/a38x/Kconfig"

arch/arm/mach-imx/mx3/Kconfig

+if ARCH_MX31
+
+config MX31
+       bool
+       default y
+choice
+	prompt "MX31 board select"
+	optional
+
+config TARGET_MX31PDK
+	bool "Support the i.MX31 PDK board from Freescale/NXP"
+	select BOARD_LATE_INIT
+	select SUPPORT_SPL
+	select BOARD_EARLY_INIT_F
+
+endchoice
+
+source "board/freescale/mx31pdk/Kconfig"
+
+endif

configs/mx31pdk_defconfig

 CONFIG_ARM=y
 # CONFIG_SPL_USE_ARCH_MEMCPY is not set
 # CONFIG_SPL_USE_ARCH_MEMSET is not set
-CONFIG_TARGET_MX31PDK=y
+CONFIG_ARCH_MX31=y
 CONFIG_SYS_TEXT_BASE=0x87e00000
 CONFIG_SPL_LIBGENERIC_SUPPORT=y
+CONFIG_TARGET_MX31PDK=y
 CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_SPL=y

include/configs/mx31pdk.h

@@ -16,8 +16,6 @@
 #include <asm/arch/imx-regs.h>
 
 /* High Level Configuration Options */
-#define CONFIG_MX31			/* This is a mx31 */
-
 #define CONFIG_CMDLINE_TAG			/* enable passing of ATAGs */
 #define CONFIG_SETUP_MEMORY_TAGS
 #define CONFIG_INITRD_TAG