linux-wandboard

MLK-11570-02 ASoC: wm8994: store/restore context in codec driver suspend/resume

For lpsr mode, the codec will be power down, the register value will be lost,
so we should store the context at the end of codec suspend, and load the
registers at the beginning of codec resume.

Signed-off-by: Zidan Wang <zidan.wang@freescale.com>
(cherry picked from commit e35e15983e14caf48dadf235bc6b33014818c62e)