The MMC module clocks on sun8i are the same as those found on
previous Allwinner SoCs, module 0 clocks.

This patch adds the clocks nodes to the dtsi with existing drivers.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>