configs: ns3: enable mmc commands

Enable mmc commands for NS3.

Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/bcm_ns3_defconfig b/configs/bcm_ns3_defconfig
index 432237b..a1ee866 100644
--- a/configs/bcm_ns3_defconfig
+++ b/configs/bcm_ns3_defconfig
@@ -14,6 +14,8 @@
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="u-boot> "
 CONFIG_SYS_XTRACE="n"
+CONFIG_CMD_MMC=y
+CONFIG_CMD_MMC_SWRITE=y
 # CONFIG_CMD_PINMUX is not set
 # CONFIG_CMD_SOURCE is not set
 CONFIG_OF_CONTROL=y