mfd: pm8038: Enable the battery alarm module

The battery alarm module provides interrupts when the battery
falls below or rises above a programmed threshold. This feature
is useful to wakeup the device when the battery is in low voltage
situations.

CRs-Fixed: 372690
Change-Id: Ia227cae58cc5f28fdd0dd81b11c9640c442b2f21
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>