MIPS: ATH79: Avoid a kernel bug on AR913X

Wireless mac registration causes a BUG on AR913X SoCs due to
a missing 'else'.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3182/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/ath79/dev-wmac.c

@@ -96,7 +96,7 @@ void __init ath79_register_wmac(u8 *cal_data)
 {
 	if (soc_is_ar913x())
 		ar913x_wmac_setup();
-	if (soc_is_ar933x())
+	else if (soc_is_ar933x())
 		ar933x_wmac_setup();
 	else
 		BUG();