ASoC: wcd_mbhc_v2: fix the device switch latency in voice call

The error logging adds the delay during the PA on and off
which results the high latency during the device switch.
Fix the issue by modifying it to debug logs.

CRs-Fixed: 749688
Change-Id: I9d83ba5916e749bf990dcb4636da81e8c615f763
Signed-off-by: Aviral Gupta <aviralg@codeaurora.org>