This enables the new Amlogic Meson MX SDIO/MMC controller driver, which
typically connects to the SD card and SDIO wifi module.
The driver is enabled as built-in to allow booting from the SD card.
Signed-off-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: NKevin Hilman <khilman@baylibre.com>