ASoC: aw8896: add resume/suspend methods for codec driver

Add resume/suspend methods for aw8896 codec driver to control LDO supply
for PA chip's DVDD pin so as to lower the power consumption when device
get in suspend mode.

Change-Id: I9a5ec5350e4fbe22794abb1e063b28a3aeae0e48
Signed-off-by: Xiao Li <lixiao@codeaurora.org>