arm64: dts: mediatek: mt6795: Add support for eMMC/SD/SDIO controllers

Add the mmc nodes to support all of the four controllers, used for
eMMC, SD/MicroSD and SDIO storage.
All of these controller nodes are left disabled by default, as
usage is board dependent.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221027095504.37432-5-angelogioacchino.delregno@collabora.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>