configs: sdm660: Fix high voice RX gain in handset mode

For WSA8810, gain setting should be G_3_DB for handset
speaker mix control to achieve -9dB digital volume.
Update mixer control to G_3_DB in handset device.

CRs-Fixed: 2011146
Change-Id: If966ed1c91317a9e770a793e9dac151e3098baff
1 file changed