asoc: codecs: Make compander write coefficients as volatile

Make HPHL and HPHR compander write coefficients as volatile
registers in order to avoid cache operations on these registers
to fix audio glitch issues in headset playback.

Change-Id: If5a2019debdda3c50cc5cf1135dff2ad0e5a49a2
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>