mmc: omap_hsmmc: add hibernation support

Setting a dev_pm_ops suspend/resume pair but not a set of
hibernation functions means those pm functions will not be
called upon hibernation.
Fix this by using SET_SYSTEM_SLEEP_PM_OPS, which appropriately
assigns the suspend and hibernation handlers and move
omap_hsmmc_x callbacks under CONFIG_PM_SLEEP to avoid build warnings.

Signed-off-by: Russ Dill <Russ.Dill@ti.com>
[Grygorii.Strashko@linaro.org: rebased on top of K4.0]
Signed-off-by: Grygorii Strashko <grygorii.strashko@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>