armv8: ls1043ardb_sdcard: prepare falcon boot

Due to a conflict with recent Primary Protected Application (PPA),
PPA cannot be loaded for SPL stage, falcon boot is not enabled by
default. With compatible PPA image, to enable falcon boot, activate
these Kconfig options in defconfig
CONFIG_SPL_FIT=y
CONFIG_SPL_FSL_LS_PPA=y
CONFIG_SPL_GZIP=y
CONFIG_SPL_LOAD_FIT=y
CONFIG_SPL_OS_BOOT=y
CONFIG_SPL_OF_LIBFDT=y

Because environment variables are not avaiable during SPL stage for
SD boot, set "boot_os=y" as default.

Signed-off-by: York Sun <york.sun@nxp.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/ls1043ardb.h b/include/configs/ls1043ardb.h
index da87497..f9843f5 100644
--- a/include/configs/ls1043ardb.h
+++ b/include/configs/ls1043ardb.h
@@ -46,6 +46,11 @@
 
 #ifdef CONFIG_SD_BOOT
 #define CONFIG_SYS_FSL_PBL_RCW board/freescale/ls1043ardb/ls1043ardb_rcw_sd.cfg
+#define CONFIG_CMD_SPL
+#define CONFIG_SYS_SPL_ARGS_ADDR	0x90000000
+#define CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR	0x10000
+#define CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR	0x500
+#define CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS	30
 #endif
 
 /*