qcacmn: Do not allocate buffers for buffer ring in smart monitor mode
Smart monitor mode requires buffers on monitor status ring only.
It does not require any buffers on monitor buffer ring.
As an optimization, initialization of descriptor pool and allocation
of buffers for monitor buffer ring is not required. Also filter
settings for monitor buffer ring are not required in smart monitor
mode.
Change-Id: If328b08184865e5472425b5520dd0a364a478c40
CRs-Fixed: 2965717