ASoC: msm8x16-wcd: fix to reduce tx pop

Add delay before the txfe init is asserted and
deasserted to ensure that the input voltage level
is properly sampled to avoid digital saturation.
Also, use the analog hpf switch to reduce the
pop level.

CRs-Fixed: 687904
Change-Id: Ie9e79a6f93c87db826b2f99d0a8c81b5fd38fb16
Signed-off-by: Aravind Kumar <akumark@codeaurora.org>