ASoC: wcd9320: Add support for notification of codec events

Add Support for machine driver to register for codec event. Machine
driver needs do one time ADSP AFE configuration after codec
initialization after ADSP SSR. So add support for machine driver to
register for codec initialization event.

CRs-Fixed: 487983
Change-Id: I3e4a392659ae8c88d845f5337760fda3af94a117
Signed-off-by: Kiran Kandi <kkandi@codeaurora.org>