ASoC: sdm660_cdc: Update mbhc reg struct for IN2P_CLAMP_STATE

Since entry for "WCD_MBHC_IN2P_CLAMP_STATE"
is missing in mbhc reg structure of analog codec,
mbhc reg indexing is going wrong.
Update this missing entry to align with the mbhc driver
reg function indexing.

Change-Id: Ia450cbbe159d0040bdaafcbbd4024cf3a36f1507
Signed-off-by: Soumya Managoli <smanag@codeaurora.org>