ARM: rmobile: Add missing config bits

The commit "fb82fe385173 configs: Resync defconfigs" resynced all config
files.  This exposed two latent issues with the Gen3 boards in that we
had not been setting CONFIG_DEFAULT_FDT_FILE correctly and had not been
setting CONFIG_CMD_MMC.  Fix both of these.

Fixes: fb82fe385173 ("configs: Resync defconfigs")
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/r8a7795_salvator-x_defconfig b/configs/r8a7795_salvator-x_defconfig
index 0d0f077..c0e3999 100644
--- a/configs/r8a7795_salvator-x_defconfig
+++ b/configs/r8a7795_salvator-x_defconfig
@@ -3,9 +3,11 @@
 CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_RCAR_GEN3=y
 CONFIG_TARGET_SALVATOR_X=y
+CONFIG_DEFAULT_FDT_FILE="r8a7795-salvator-x.dtb"
 CONFIG_VERSION_VARIABLE=y
 CONFIG_CMD_BOOTZ=y
 # CONFIG_CMD_IMLS is not set
+CONFIG_CMD_MMC=y
 CONFIG_CMD_USB=y
 CONFIG_CMD_DHCP=y
 CONFIG_CMD_MII=y