ASoC: sdm660: Update VI sense sample rate to 8k

SR was changed from 8kHz to 48kHz due to capturing
of garbled VI sense data as per HW team suggestion.
With new speaker protection algo in dsp, 8kHz is
expected and earlier issue with 8kHz is not seen.
Reverting the SR change back to 8kHz.

CRs-Fixed: 2364486
Change-Id: I379a080eb17e7a82fe87608f89dcbfa5444e8916
Signed-off-by: Soumya Managoli <smanag@codeaurora.org>