input: qpnp-power-on: Cleanup the qpnp-power-on driver

Fix the following in qpnp-power-on driver:
- Use GENMASK for bit mask
- Remove unused module parameter
- Use nested comments properly wherever applicable
- Fix conditional block formatting and typos
- Use const qualifier for of_device_id table

Change-Id: Ib9dd9be6cafad4c7aec1c88d9828ef1ebbe2a1c3
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>