arm64: allwinner: a64: add UART1 pin nodes

On many boards UART1 connects to a Bluetooth chip, so add the pinctrl
nodes for the only pins providing access to that UART. That includes
those pins for hardware flow control (RTS/CTS).

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>

arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi

@@ -275,6 +275,16 @@
 				pins = "PB8", "PB9";
 				function = "uart0";
 			};
+
+			uart1_pins: uart1_pins {
+				pins = "PG6", "PG7";
+				function = "uart1";
+			};
+
+			uart1_rts_cts_pins: uart1_rts_cts_pins {
+				pins = "PG8", "PG9";
+				function = "uart1";
+			};
 		};
 
 		uart0: serial@1c28000 {