arm64: dts: allwinner: a64: Rename r_i2c_pins_a label to r_i2c_pl89_pins

The pinmux name and label for a specific function should denote which
pingroup it is on, or if there is only one option for the function, have
not enumerating prefix/suffix at all.

The "r_i2c_pins_a" label is renamed to "r_i2c_pl89_pins" to fit our
current style. The node name "i2c" is also changed to "r-i2c-pl89-pins"
to match. The reason for the peculiar name is that the other option for
muxing R_I2C is on the PL0/PL1 pins, so the name has to mention the pin
numbers in addition to the pingroup.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>

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

@@ -142,7 +142,7 @@ axp803: pmic@3a3 {
 &r_i2c {
 	clock-frequency = <100000>;
 	pinctrl-names = "default";
-	pinctrl-0 = <&r_i2c_pins_a>;
+	pinctrl-0 = <&r_i2c_pl89_pins>;
 	status = "okay";
 };
 

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

@@ -770,7 +770,7 @@ r_pio: pinctrl@1f02c00 {
 			interrupt-controller;
 			#interrupt-cells = <3>;
 
-			r_i2c_pins_a: i2c-a {
+			r_i2c_pl89_pins: r-i2c-pl89-pins {
 				pins = "PL8", "PL9";
 				function = "s_i2c";
 			};