mac80211: include brcmfmac firmware for BCM43602

It can be found e.g. in Netgear R8000.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44915 3c298f89-4303-0410-b956-a3cf2f4a3e73