[][dts: mt7986: Fix & isolate pinctrl & flash partition]

[Description]
Fix and isolate pinctrl & flash partition:
1. There are common parts for pinctrl, which we used to
put them in dts. Isolate them into dtsi to avoid lots of
repetition.
2. Isolate flash fixed-partitions so we could modify
easily.

[Release-log]
N/A

Change-Id: Ie4c8add82924445bd00b9139ff4f1a0177eb55ec
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/5053659
diff --git a/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7986a-pinctrl.dtsi b/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7986a-pinctrl.dtsi
new file mode 100644
index 0000000..42619a1
--- /dev/null
+++ b/target/linux/mediatek/files-5.4/arch/arm64/boot/dts/mediatek/mt7986a-pinctrl.dtsi
@@ -0,0 +1,141 @@
+&pio {
+	wifi_led_pins: wifi_led-pins-1-2 {
+		mux {
+			function = "led";
+			groups = "wifi_led";
+		};
+	};
+
+	i2c_pins: i2c-pins-3-4 {
+		mux {
+			function = "i2c";
+			groups = "i2c";
+		};
+	};
+
+	uart1_pins_g0: uart1-pins-7-to-10 {
+		mux {
+			function = "uart";
+			groups = "uart1_0";
+		};
+	};
+
+	pcie0_pins: pcie0-pins-9-10-41 {
+		mux {
+			function = "pcie";
+			groups = "pcie_clk", "pcie_wake", "pcie_pereset";
+		};
+	};
+
+	jtag_pins: jtag-pins-11-to-14 {
+		mux {
+			function = "jtag";
+			groups = "jtag";
+		};
+	};
+
+	spic_pins_g0: spic-pins-11-to-14 {
+		mux {
+			function = "spi";
+			groups = "spi1_0";
+		};
+	};
+
+	pwm1_pin_g0: pwm1-pin-20 {
+		mux {
+			function = "pwm";
+			groups = "pwm1_1";
+		};
+	};
+
+	pwm0_pin: pwm0-pin-21 {
+		mux {
+			function = "pwm";
+			groups = "pwm0";
+		};
+	};
+
+	pwm1_pin_g1: pwm1-pin-22 {
+		mux {
+			function = "pwm";
+			groups = "pwm1_0";
+		};
+	};
+
+	spic_pins_g1: spic-pins-23-to-26 {
+		mux {
+			function = "spi";
+			groups = "spi1_1";
+		};
+	};
+
+	uart1_pins_g1: uart1-pins-23-to-26 {
+		mux {
+			function = "uart";
+			groups = "uart1_1";
+		};
+	};
+
+	spic_pins_g2: spic-pins-29-to-32 {
+		mux {
+			function = "spi";
+			groups = "spi1_2";
+		};
+	};
+
+	uart1_pins_g2: uart1-pins-29-to-32 {
+		mux {
+			function = "uart";
+			groups = "uart1_2";
+		};
+	};
+
+	uart2_pins_g0: uart1-pins-29-to-32 {
+		mux {
+			function = "uart";
+			groups = "uart1_2";
+		};
+	};
+
+	uart2_pins_g1: uart1-pins-23-to-36 {
+		mux {
+			function = "uart";
+			groups = "uart2_1";
+		};
+	};
+
+	spic_pins_g3: spic-pins-33-to-36 {
+		mux {
+			function = "spi";
+			groups = "spi1_3";
+		};
+	};
+
+	uart1_pins_g3: uart1-pins-35-to-38 {
+		mux {
+			function = "uart";
+			groups = "uart1_3_rx_tx", "uart1_3_cts_rts";
+		};
+	};
+
+	uart1_pins: uart1-pins-42-to-45 {
+		mux {
+			function = "uart";
+			groups = "uart1";
+		};
+	};
+
+	uart2_pins: uart1-pins-46-to-49 {
+		mux {
+			function = "uart";
+			groups = "uart2";
+		};
+	};
+
+	pcm_pins: pcm-pins-62-to-65 {
+		mux {
+			function = "pcm";
+			groups = "pcm";
+		};
+	};
+};