SPL: Move SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION to Kconfig

Added SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION and
SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION to Kconfig.

Due to SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION being moved to
Kconfig the board defconfigs for db-88f6820-gp_defconfig
kc1_defconfig and sniper_defconfig need to be updated.

Signed-off-by: Dalon Westergreen <dwesterg@gmail.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0229800..e84b74e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -633,6 +633,7 @@
 	select ENABLE_ARM_SOC_BOOT0_HOOK
 	select ARCH_EARLY_INIT_R
 	select ARCH_MISC_INIT
+	select SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION
 
 config TARGET_CM_T43
 	bool "Support cm_t43"