mfd: tps65910: Add alarm interrupt of TPS65910 RTC to mfd device list

Add RTC alarm interrupt details to TPS65910 MFD device list, to support
RTC alarm events.

Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>