mmc: omap_hsmmc: remove unused fields in platform_data

platform data is built from omap2_hsmmc_info, remove all fields that
are never set in omap_hsmmc_info, hence never copied to platform data.
Note that the omap_hsmmc driver is not affected by this patch those
fields were completely unused.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andreas Fenkart <afenkart@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>