x86: sound: Add sound support for samus (broadwell)

Add a sound driver for samus which ties together the audio codec and
I2S controller.

For now broadwell_sound is commented out in the makefile since we cannot
compile it without sound support enabled. The next commit fixes this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>