asoc: codec: avoid out of bound write to map array

added check for port num and channel iteration are lessthan 8
to avoid out of bound write to 8x8 map array.

Change-Id: I4c6fe13a5eb09be623a1c40ce16c5a5e4246e021
Signed-off-by: Abinath S <quic_abins@quicinc.com>