Add SDHI0 and SDHI2 interfaces to kzm9g-reference. With no pinctrl DT
support we cannot use GPIO card-detection and regulator switching.
Also update the MMCIF DT node to use all 8 data lines and avoid
redundant information in DT.

Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
[ horms+renesas@verge.net.au: Updated for pinmux changes by Laurent Pinchart ]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>