mmc: host: omap_hsmmc: use the ocrmask provided by the vmmc regulator

If the vmmc regulator provides a valid ocrmask, use it. By this even if
the pdata has a valid ocrmask, it will be overwritten with the ocrmask
of the vmmc regulator.
Also remove the unnecessary compatibility check between the ocrmask in
the pdata and the ocrmask from the vmmc regulator.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>