Regulator: TWL6030: Unmask PREQ in MASK_TRANSITION.

Based on board configuration, unmask PREQ so that on de-assertion
or assertion on PREQ{1,2,3} transition Executes ACT2SLP and
SLP2ACT sleep sequence.

By default APPs process group is unmasked, but can be overridden
through board file using struct twl4030_power_data.

Change-Id: Ib9f561c64210e5997865a4bf7a2203dca9a1d695
Signed-off-by: Ambresh K <ambresh@ti.com>
config dump

Signed-off-by: Willi Ye <williye97@gmail.com>