Add separate compatible strings for every platform and populate the
pbias register offset in the driver data.
This helps avoid depending on the dt for pbias register offset.

Also update the dt binding documentation for the new compatible
strings.
Suggested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

pbias register controls internal power supply to sd card i/o pads
in most OMAPs (OMAP2-5, DRA7).
Control bits for selecting voltage level and
enabling/disabling are in the same PBIAS register.
Signed-off-by: NBalaji T K <balajitk@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NMark Brown <broonie@linaro.org>
Tested-by: NFlorian Vaussard <florian.vaussard@epfl.ch>
Tested-by: NStefan Roese <sr@denx.de>
Signed-off-by: NChris Ball <chris@printf.net>