ASoC: Wolfson Microelectronics 1133-EV1 audio support

Initial support for audio using the 1133-EV1 audio and PMIC module for
the i.MX31ADS.  Currently only playback is supported, and the FIQ DMA
driver has performance problems at higher sample rates which cause
audible dropouts.

This driver is based heavily on an out of tree one written by Liam
Girdwood.

Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>