mmc: omap_hsmmc: remove unused fields from struct omap_hsmmc_host

addon to: 09108968b7b72b6083a3bfc8f8259a74ed57255e
    mmc: omap_hsmmc: remove prepare/complete system suspend support

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