b43: remove leftover code from old devices support

Old devices (A-PHY or B-PHY) are supposed to be supported by b43legacy.
We keep phy_a.c as it's needed for G-PHY which shares some design.

Signed-off-by: Rafał Miłecki <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

drivers/net/wireless/b43/main.c

···
 	phy_type = (tmp & B43_PHYVER_TYPE) >> B43_PHYVER_TYPE_SHIFT;
 	phy_rev = (tmp & B43_PHYVER_VERSION);
 	switch (phy_type) {
-	case B43_PHYTYPE_A:
-		if (phy_rev >= 4)
-			unsupported = 1;
-		break;
-	case B43_PHYTYPE_B:
-		if (phy_rev != 2 && phy_rev != 4 && phy_rev != 6
-		    && phy_rev != 7)
-			unsupported = 1;
-		break;
 	case B43_PHYTYPE_G:
 		if (phy_rev > 9)
 			unsupported = 1;

drivers/net/wireless/b43/phy_a.h

···
  */
 void b43_phy_inita(struct b43_wldev *dev);
 
-
-struct b43_phy_operations;
-extern const struct b43_phy_operations b43_phyops_a;
-
 #endif /* LINUX_B43_PHY_A_H_ */

drivers/net/wireless/b43/phy_common.c

···
 	phy->ops = NULL;
 
 	switch (phy->type) {
-	case B43_PHYTYPE_A:
-		phy->ops = &b43_phyops_a;
-		break;
 	case B43_PHYTYPE_G:
 		phy->ops = &b43_phyops_g;
 		break;