Added support for CS5343/CS5344 ADC connected to the Raspberry Pi

I have implemented support for the CS5343/CS5344 98 dB, 96 kHz, Multi-Bit Audio A/D Converter (configured for sampling rate 48 kHz) , connected to the Raspberry Pi I2S interface.
These files were previously submitted to the branch rpi-3.8.y.asocdev in https://github.com/koalo/linux
This version is ported to the new driver for 3.12.y kernel and successfully tested with the real hardware (https://github.com/wzab/raspberry-pi-guitar-system-v1)