ASoC: wcd9xxx: Remove unnecessary condition

There is no need to check if internal micbias is
already enabled when we are only updating the bits,
as updating the bits does not do register write
if bit is already set.

CRs-Fixed: 572295
Change-Id: I79ea05150c6d3a2bbaeff0ac66bd39888451f11d
Signed-off-by: Simmi Pateriya <simmip@codeaurora.org>