ARM: dts: meson8: add the uart_A pins

This adds the pins for uart_A, which is used to connect to the Bluetooth
module on some devices.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

arch/arm/boot/dts/meson8.dtsi

@@ -281,6 +281,22 @@ mux {
 				function = "pwm_e";
 			};
 		};
+
+		uart_a1_pins: uart-a1 {
+			mux {
+				groups = "uart_tx_a1",
+				       "uart_rx_a1";
+				function = "uart_a";
+			};
+		};
+
+		uart_a1_cts_rts_pins: uart-a1-cts-rts {
+			mux {
+				groups = "uart_cts_a1",
+				       "uart_rts_a1";
+				function = "uart_a";
+			};
+		};
 	};
 };