msm: qca1530: Sysfs control and optional power regulator

Sysfs based control for the driver added to save power
switching off unnecessary HW resources. Driver shows chip_state
node that supports read/write access and turns HW resources
on/off. Optional power regulator control added that is required
on certain platfroms in addition to the main one.

Change-Id: I5bb52f1eb320f45c0a659ca078fd98d887ef89f7
Signed-off-by: Roman Gezikov <rgezikov@codeaurora.org>