configs: shima: Change tx ADC mode as LP by default

Change tx ADC mode as LP by default for audio record to
work in LP mode by default. Also change backend for fm
as tert mi2s instead of slimbus 8.

Change-Id: Ie9ee4af40692461e8b1ec149e4322e54fc55102d
Signed-off-by: Vatsal Bucha <vbucha@codeaurora.org>