Added support for Wolfson Audio Card by Element-14

Hi All,

Please find the patches to support Element 14 Wolfson Audio Card. 

The patch bundle includes the machine driver and few other supporting patches to offer the functionality of WM5102 and WM8804 codecs drivers.
None of these patches needs to be pushed to Linux mainline as these are RPI specific. 

The current patch-set does not support SPDIF functionality. We are working on a patch-set that will be pushed to the mainline Kernel and once these have been merged we will submit them for addition in to the raspberry-pi kernel.

For your reference, the following link takes you to the official product page.
http://www.element14.com/community/community/raspberry-pi/raspberry-pi-accessories/wolfson_pi?CMP=KNC-EU-RPI-ACC-Wolfson

~Manish Gupta