dsp: q6voice: Add buf size check for cvs cal data

Check for the max size of cvs command register
calibration data that can be copied else will
result in buffer overflow.

Change-Id: Id7a4c5a9795143798b68dfde779f17fb450e3848
Signed-off-by: Soumya Managoli <quic_c_smanag@quicinc.com>