ASoC: msm: set IIR1 gain after IIR clock is enable

Sidetone gain is not getting applied when provide gain
value from mixers_path.xml(IIR1 INP1 Volume). The problem
is the volume control is applied before IIR clock/power is
enabled reason is controls to enable the clock are
registered with soc-dapm framework and volume control is
registered with soc-core framework and gets applied before.
Fix is to register a post power up handler with IIR1 clock
power/control widget. This handler reads  register value of
volume gain and re-apply it.

CRs-Fixed: 675099
Change-Id: I32c6de0f20e5e98cab6cddeefac53b8d86d5b71a
Signed-off-by: Ramjee Singh <ramjee@codeaurora.org>