ASoC: msm8x16-wcd: restore the speaker boost control

To maintain same design across chipsets,
to disable or enable speaker/EAR boost controls,
restore the speaker boost control which can be
set to ENABLE/DISABLE using mixer XML file.
Clients can choose the configuration based on
design needs.

CRs-Fixed: 1002094
Change-Id: I4687b819009a3b57c3b0070b4de60e7b5451e664
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>