To support network namespace the driver must assure all created
network interfaces are in the same namespace as the wiphy instance
and flag the support using WIPHY_FLAG_NETNS_OK.

Verified using two terminals:

 Terminal 1			Terminal 2
 --------------------------	---------------------------------
 # ip netns add brcm-wifi	# iw dev
				phy#0
					Interface wlan3
						ifindex 11
						wdev 0x1
 # ip netns exec brcm-wifi bash
 # iw dev
 # echo $$
 20337			# iw phy0 set netns 20337
 # iw dev
 phy#0
	Interface wlan3
		ifindex 11
		wdev 0x2
 # iw phy0 interface add wl3.ap type __ap
 # iw dev
 phy#0
	Interface wl3.ap
		ifindex 2
		wdev 0x3
	Interface wlan3
		ifindex 11
		wdev 0x2
				# iw dev
 # iw phy0 set netns 1
 # iw dev
				# iw dev
				phy#0
					Interface wl3.ap
						ifindex 2
						wdev 0x5
					Interface wlan3
						ifindex 11
						wdev 0x4

Note:
	increasing wdev identifier above indicates issue in
	cfg80211 which is addressed separately.
Tested-by: Mark Asselstine <mark.asselstine@windriver.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>