hal: Check input buffer size as multiple of channel

Update get input buffer size logic for record use cases
such that the size is also a multiple of bytes per sample
period. For 6 channel 32 bit recording the computed
value was not a multiple of bytes per sample and this
mismatches with the computed value by ALSA causing
buffer invalid errors because the use case pointers
difference was reaching stop threshold.

Change-Id: Ibca14baf26334888819cd15db39626b63c14f626