ASoC: msm8930: Add speaker playback support for 8930+8917

PM8917 does not have speaker amplifier, hence the codec lineout
is directed to the speaker through a onboard amplifier. The
amplifier needs to be enabled in order for speaker playback
to work on a target with PM8917

Change-Id: Ic9f16d335bc1a0cef6fb1eb93c1617fd086cc5b7
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>