asoc: bolero: add different unmute_delay for AMIC and DMIC

unmute_delay for AMIC and DMIC may be different and use same
flag may affect the powerup time. Add different unmute_delay
flag for AMIC and DMIC to resolve the issue.

Change-Id: I7697b1fae92a2b37530106c1c7b79a5d1bd74021
Signed-off-by: Meng Wang <mengw@codeaurora.org>