mfd: wcd9xxx-irq: add pm awake and relax to hold wake lock

To honor codec interrupts, after pm qos update request is
sent, awake/relax apis need to be called otherwise to keep
system awake to process any interrupts from the codec.

CRs-Fixed: 776130
Change-Id: I2fb25d58947b638a4b650e499172ae029edfad19
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>