ARM: ep93xx: enable SIM.ONE MMC/SD hardware

The SIM.ONE has a MMC card connected to the SPI host. This card
usually hosts an EXT4 root file system. Enable these options in
the defconfig so the default ompiled kernel will work
out-of-the-box.

Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>