configs: e850-96: Enable MMC

Enable MMC subsystem and DW MMC driver support to make eMMC functional.
Also enable a couple of related commands so the user can make use of
eMMC from U-Boot shell.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
1 file changed