arm64: dts: mt7622: add ePA/eLNA pinmux for built-in WiFi

This just illustrates one of possible combinations. User should setup
the corresponding pins according to the onboard RF data that stores
in eeprom.
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Link: https://lore.kernel.org/r/641c5e40f54e7c9c8eaa6be398d7169445b6fede.1617006498.git.ryder.lee@mediatek.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts

@@ -495,6 +495,16 @@ mux {
 			groups = "watchdog";
 		};
 	};
+
+	wmac_pins: wmac-pins {
+		mux {
+			function = "antsel";
+			groups = "antsel0", "antsel1", "antsel2", "antsel3",
+				 "antsel4", "antsel5", "antsel6", "antsel7",
+				 "antsel8", "antsel9", "antsel12", "antsel13",
+				 "antsel14", "antsel15", "antsel16", "antsel17";
+		};
+	};
 };
 
 &pwm {
@@ -559,5 +569,7 @@ &watchdog {
 };
 
 &wmac {
+	pinctrl-names = "default";
+	pinctrl-0 = <&wmac_pins>;
 	status = "okay";
 };