cnss2: Add level for low latency bandwidth voting

Add an additional bandwidth level for voting in
latency critical cases for low throughputs.

CRs-Fixed: 2695123
Change-Id: Ibb7ae83bf782bff5a9651caa3df3088eea29a8ae
Signed-off-by: Rakesh Pillai <pillair@codeaurora.org>