drivers/rtc/rtc-tps65910.c: use sleep_pm_ops macro for initialising suspend/resume callbacks

Use SET_SYSTEM_SLEEP_PM_OPS for setting suspend/resume callbacks for
dev_pm_ops.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>