ASoC: wcd9335: Update sidetone enable register sequence

Channel-level sidetone enable registers need to be set
for the sidetone to work properly. Update the sidetone
channel-level registers correctly.

Change-Id: Ibb41228609cdf360bfe03c9261066d5d4e378e30
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>