ASoC: msm: Fix qcom aac enc - allow alloc of less buffers

Commit "SoC: msm: Add Buffer overflow check" strictly enforces
buffer count to 8, otherwise allocation will fail, which breaks
qcom hw aac encoder. To fix it, allow the buffer count to be 8
or less.

Change-Id: Ia554bde6058abd7ff5447fd69b517217eb83d59c
Build v0.47