qcacmn: Add get Chan DFS attribute API

DFS chan "state" will be set to CHANNEL_STATE_DISABLE
if the dfs chan is added to NOL.
Add the new API wlan_reg_chan_has_dfs_attribute
to get the attribute from "chan_flag" which keeps
the chan's initial dfs attribute.

Change-Id: I5149d958c0dcb1e5909e02bd5be9acdf9fca7f2f
CRs-Fixed: 2324648
4 files changed