codec2: increase max dequeue output buffer count

Add # of input slots to max dequeue buffer count for output buffers.
If pipeline is paused, # of output buffers could be whole pipeline depth
including # of input slots.

Bug: 137150765
Merged-In: I5fce613a383160ea8a49e77f67628f85408cdcfa
Change-Id: I5fce613a383160ea8a49e77f67628f85408cdcfa
(cherry picked from commit 7a7b742c)