ARM: shmobile: mackerel: remove OCR masks, where regulators are used

Both SDHI and MMCIF drivers ignore their OCR platform values, when
available voltages can be retrieved from regulators.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>