overlays: mcp2515: Add support for spi3 and spi5

Extend the mcp2515 overlay to support the spi3 and spi5 buses available
on newer Raspberry Pi hardware. This adds the required dormant fragments
to disable the default spidev drivers, updates the __overrides__ routing
logic, and updates the README accordingly.

Signed-off-by: Kevin Beichler <k.beichler@gmx.com>

Author: KBeichler

arch/arm/boot/dts/overlays/README

@@ -3406,9 +3406,9 @@ Params: s08-spi<n>-<m>-present  4-bit integer, bitmap indicating MCP23S08
 
 
 Name:   mcp2515
-Info:   Configures the MCP2515 CAN controller on spi0/1/2
-        For devices on spi1 or spi2, the interfaces should be enabled
-        with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
+Info:   Configures the MCP2515 CAN controller on spi0/1/2/3/5
+        For devices on spi1, spi2, spi3 or spi5, the interfaces should be
+        enabled with one of the spi<n>-1/2/3cs overlays.
 Load:   dtoverlay=mcp2515,<param>=<val>
 Params: spi<n>-<m>              Configure device at spi<n>, cs<m>
                                 (boolean, required)

arch/arm/boot/dts/overlays/mcp2515-overlay.dts

@@ -67,6 +67,34 @@
 	};
 
 	fragment@8 {
+		target-path = "spi3/spidev@0";
+		__dormant__ {
+			status = "disabled";
+		};
+	};
+
+	fragment@9 {
+		target-path = "spi3/spidev@1";
+		__dormant__ {
+			status = "disabled";
+		};
+	};
+
+	fragment@10 {
+		target-path = "spi5/spidev@0";
+		__dormant__ {
+			status = "disabled";
+		};
+	};
+
+	fragment@11 {
+		target-path = "spi5/spidev@1";
+		__dormant__ {
+			status = "disabled";
+		};
+	};
+
+	fragment@12 {
 		target = <&gpio>;
 		__overlay__ {
 			mcp2515_pins: mcp2515_pins {
@@ -76,7 +104,7 @@
 		};
 	};
 
-	fragment@9 {
+	fragment@13 {
 		target-path = "/clocks";
 		__overlay__ {
 			clk_mcp2515_osc: mcp2515-osc {
@@ -87,7 +115,7 @@
 		};
 	};
 
-	mcp2515_frag: fragment@10 {
+	mcp2515_frag: fragment@14 {
 		target = <&spi0>;
 		__overlay__ {
 			status = "okay";
@@ -118,6 +146,7 @@
 			<&mcp2515>, "reg:0=1",
 			<&mcp2515_pins>, "name=mcp2515_spi0_1_pins",
 			<&clk_mcp2515_osc>, "name=mcp2515-spi0-1-osc";
+
 		spi1-0 = <0>, "+2",
 			<&mcp2515_frag>, "target:0=", <&spi1>,
 			<&mcp2515>, "reg:0=0",
@@ -133,6 +162,7 @@
 			<&mcp2515>, "reg:0=2",
 			<&mcp2515_pins>, "name=mcp2515_spi1_2_pins",
 			<&clk_mcp2515_osc>, "name=mcp2515-spi1-2-osc";
+
 		spi2-0 = <0>, "+5",
 			<&mcp2515_frag>, "target:0=", <&spi2>,
 			<&mcp2515>, "reg:0=0",
@@ -148,6 +178,33 @@
 			<&mcp2515>, "reg:0=2",
 			<&mcp2515_pins>, "name=mcp2515_spi2_2_pins",
 			<&clk_mcp2515_osc>, "name=mcp2515-spi2-2-osc";
+
+		spi3-0 = <0>, "+8",
+			<&mcp2515_frag>, "target?=0",
+			<&mcp2515_frag>, "target-path=spi3",
+			<&mcp2515>, "reg:0=0",
+			<&mcp2515_pins>, "name=mcp2515_spi3_0_pins",
+			<&clk_mcp2515_osc>, "name=mcp2515-spi3-0-osc";
+		spi3-1 = <0>, "+9",
+			<&mcp2515_frag>, "target?=0",
+			<&mcp2515_frag>, "target-path=spi3",
+			<&mcp2515>, "reg:0=1",
+			<&mcp2515_pins>, "name=mcp2515_spi3_1_pins",
+			<&clk_mcp2515_osc>, "name=mcp2515-spi3-1-osc";
+
+		spi5-0 = <0>, "+10",
+			<&mcp2515_frag>, "target?=0",
+			<&mcp2515_frag>, "target-path=spi5",
+			<&mcp2515>, "reg:0=0",
+			<&mcp2515_pins>, "name=mcp2515_spi5_0_pins",
+			<&clk_mcp2515_osc>, "name=mcp2515-spi5-0-osc";
+		spi5-1 = <0>, "+11",
+			<&mcp2515_frag>, "target?=0",
+			<&mcp2515_frag>, "target-path=spi5",
+			<&mcp2515>, "reg:0=1",
+			<&mcp2515_pins>, "name=mcp2515_spi5_1_pins",
+			<&clk_mcp2515_osc>, "name=mcp2515-spi5-1-osc";
+
 		oscillator = <&clk_mcp2515_osc>, "clock-frequency:0";
 		speed = <&mcp2515>, "spi-max-frequency:0";
 		interrupt = <&mcp2515_pins>, "brcm,pins:0",