b43: enable 5 GHz support for N-PHY devices

This has been tested on 14e4:4328 (BCM4321), 14e4:432b (BCM4322),
14e4:4353 (BCM43224) and 14e4:4359 (BCM43228) which is an almost
complete list of 5 GHz capable device (only BCM43222 is missing).
Signed-off-by: NRafał Miłecki <zajec5@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43/main.c

@@ -5338,7 +5338,6 @@ static int b43_wireless_core_attach(struct b43_wldev *dev)
 		switch (dev->phy.type) {
 		case B43_PHYTYPE_A:
 		case B43_PHYTYPE_G:
-		case B43_PHYTYPE_N:
 		case B43_PHYTYPE_LP:
 		case B43_PHYTYPE_HT:
 			b43warn(wl, "5 GHz band is unsupported on this PHY\n");