dhd: apply old changes to updated driver

- Condense wakelock handling
- Remove oodles of debuggery
- Assorted small changes

Change-Id: I241492557614e7c20e809edd7f0646aafe388216
m2: increase volume key debounce to 8

To better differentiate long-press and short press

Change-Id: Ib2470790a95baba2b1e31baefdbd4bc5fbb0ef91