ASoC: wcd9335: Set 12dB gain for speaker playback

On IoE reference board, audio mute observed during Max volume
audio playback with 4 ohm speaker connected to WSA. 12dB gain
is ideal gain for 4 and 8 ohm speakers and recommended
by systems team.

Change-Id: I06f9663a7fdddec3a2e06c68bf8ef9821c21bf29
Signed-off-by: Viraja Kommaraju <virajak@codeaurora.org>