qcacld-3.0: Consider phy mode sent by fw to get dot11 mode

Currently, after roaming only vht ie is used to get dot11 mode
which may casue issue whenever vendor vht ie is present but vht
ie is not present in beacon. Host updates dot11 mode to
11N based on missing vht ie and does not consider vendor vht but
fw considers vendor vht ie which causes different dot11 modes in
fw and host.

Consider phy mode sent by fw in roam sync event to get dot11
mode to maintain compatibility between host and fw.

Change-Id: Ie9e4cbadd84d239c6f386f296c77677b15ce0500
CRs-Fixed: 2714566