cnss2: Add sysfs support for configuring qtimer sync interval

It can be used to tune the host and fw time synchronization interval
for better accuracy.

Change-Id: I0a3d8895520cec526341f278c91f153dd0bd1966
CRs-Fixed: 2787916
Signed-off-by: Visweswara Tanuku <vtanuku@codeaurora.org>