ASoC: wsa881x: Update read only registers as volatile

Some of the Bongo read only registers are not set as
volatile. Because of this, register values are read
incorrectly when the driver reads these registers. Fix
this issue by updating read only registers as volatile.

Change-Id: I5775b3e776beeef67874025454a0f232336cc777
Signed-off-by: Vidyakumar Athota <vathota@codeaurora.org>