mx6saberesd_spl: Correct falcon mode addition

When falcon mode support was added, it was right around when SPL_OS_BOOT
was migrated to Kconfig.  So first we must move the enablement to the
defconfig file.  Next, it turned off EXT support rather than add the
information to allow for falcon mode from EXT.  Add this information so
that the board compiles after 5d28b930f237.

Fixes: d96796ca23b2 ("mx6sabresd: Add Falcon mode support")
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/mx6sabresd.h b/include/configs/mx6sabresd.h
index 10c229d..598ab9a 100644
--- a/include/configs/mx6sabresd.h
+++ b/include/configs/mx6sabresd.h
@@ -11,7 +11,6 @@
 
 #ifdef CONFIG_SPL
 #include "imx6_spl.h"
-#undef CONFIG_SPL_EXT_SUPPORT
 #endif
 
 #define CONFIG_MACH_TYPE	3980
@@ -24,8 +23,9 @@
 #include "mx6sabre_common.h"
 
 /* Falcon Mode */
+#define CONFIG_SPL_FS_LOAD_ARGS_NAME	"args"
+#define CONFIG_SPL_FS_LOAD_KERNEL_NAME	"uImage"
 #define CONFIG_CMD_SPL
-#define CONFIG_SPL_OS_BOOT
 #define CONFIG_SYS_SPL_ARGS_ADDR       0x18000000
 #define CONFIG_CMD_SPL_WRITE_SIZE      (128 * SZ_1K)