qcacmn: Remove unnecessary assert in qdf_mc_timer_start
Currently, driver asserts whenever there is a request to
start timer with an expiration limit of less than 10ms. This
assert is unnecessary and driver should gracefully reject the
request. So, remove the assert in qdf_mc_timer_start.
CRs-Fixed: 3631848
Change-Id: Ib7c6297528d5ced3c61e6183ea8e62c12ea9cb0d