configs: atoll: Modify the decimator gain for DMIC3 use cases

DMIC3 in atoll target uses higher sensitivity mic which
leads to secondary mic picking higher volume
than the primary mic. Adjust the decimator gain for DMIC3
to 84dB to fix this issue.

Change-Id: Ib5de8d45a806c37155d15688e66b447bc5f2125b
2 files changed