qcacld-3.0: Update rate flags correctly

Currently driver does not update the rate flags correctly
in wma as rate flags should include all the subsets of the
lower rate sets, which is not the case today and driver only
updates the higher rate flag. Because of which it leads to
invalid computation of txrate at the kernel.

To address this issue, update the rate flags correctly in
wma.

Change-Id: I5529532b3d41b68693b5b4b8952ee0f1414354db
CRs-Fixed: 2776370