MMC: Add support for the controller on JZ4740 SoCs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Matt Fleming <matt@console-pimps.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Fleming <matt@console-pimps.org>
Cc: linux-mmc@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1463/
Patchwork: https://patchwork.linux-mips.org/patch/1523/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>