Add capture support to msm8x16-wcd codec

Add capture support to msm8x16-wcd codec

This patch adds msm8x16-wcd codec support which has been tested for
Audio In using Headset Mic/Secondary Mic/Primary Mic and Audio out via
Speaker/Headset.

Below are mixer setups for capture and playbacks.

amixer cset numid=18,iface=MIXER,name='RX1 MIX1 INP1' 'RX1'
amixer cset numid=21,iface=MIXER,name='RX2 MIX1 INP1' 'RX2'
amixer cset numid=5,iface=MIXER,name='RX1 Digital Volume' 100
amixer cset numid=6,iface=MIXER,name='RX2 Digital Volume' 100
amixer cset numid=30,iface=MIXER,name='RDAC2 MUX' 'RX2'

amixer cset numid=23,iface=MIXER,name='RX3 MIX1 INP1' 'RX1'
amixer cset numid=17,iface=MIXER,name='SPK DAC Switch' 1

amixer cset numid=28,iface=MIXER,name='DEC1 MUX' 'ADC2'
amixer cset numid=3,iface=MIXER,name='ADC2 Volume' 70
amixer cset numid=27,iface=MIXER,name='ADC2 MUX' 'INP2'
arecord -D plughw:0,2 -r 16000 -f S16_LE /tmp/f-16000.wav

amixer cset numid=28,iface=MIXER,name='DEC1 MUX' 'ADC2'
amixer cset numid=3,iface=MIXER,name='ADC2 Volume' 70
amixer cset numid=27,iface=MIXER,name='ADC2 MUX' 'INP3'

amixer cset numid=27,iface=MIXER,name='DEC1 MUX' 'DMIC1'

TODO:
headset jack/Mic detection
headset Buttons

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>