arm64: dts: mediatek: mt7988: move uart0 and spi1 pins to soc dtsi

In order to use uart0 or spi1 there is only 1 possible pin definition
so move them to soc dtsi to reuse them in other boards and avoiding
conflict if defined twice.

Suggested-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Link: https://lore.kernel.org/r/20250516180147.10416-7-linux@fw-web.de
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Author: frank-w

arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dtsi

@@ -328,13 +328,6 @@
 		};
 	};
 
-	uart0_pins: uart0-pins {
-		mux {
-			function = "uart";
-			groups =  "uart0";
-		};
-	};
-
 	snfi_pins: snfi-pins {
 		mux {
 			function = "flash";
@@ -356,13 +349,6 @@
 		};
 	};
 
-	spi1_pins: spi1-pins {
-		mux {
-			function = "spi";
-			groups = "spi1";
-		};
-	};
-
 	spi2_pins: spi2-pins {
 		mux {
 			function = "spi";

arch/arm64/boot/dts/mediatek/mt7988a.dtsi

@@ -209,6 +209,20 @@
 						 "pcie_wake_n3_0";
 				};
 			};
+
+			spi1_pins: spi1-pins {
+				mux {
+					function = "spi";
+					groups = "spi1";
+				};
+			};
+
+			uart0_pins: uart0-pins {
+				mux {
+					function = "uart";
+					groups =  "uart0";
+				};
+			};
 		};
 
 		pwm: pwm@10048000 {
@@ -244,6 +258,8 @@
 			clocks = <&topckgen CLK_TOP_UART_SEL>,
 				 <&infracfg CLK_INFRA_52M_UART0_CK>;
 			clock-names = "baud", "bus";
+			pinctrl-names = "default";
+			pinctrl-0 = <&uart0_pins>;
 			status = "disabled";
 		};
 
@@ -338,6 +354,8 @@
 				      "hclk";
 			#address-cells = <1>;
 			#size-cells = <0>;
+			pinctrl-names = "default";
+			pinctrl-0 = <&spi1_pins>;
 			status = "disabled";
 		};