overlays: Add overlay_map

The overlay map permits platform-specific overlays, with deprecation
and renaming.

See: #3520

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

arch/arm/boot/dts/overlays/Makefile

@@ -1,5 +1,7 @@
 # Overlays for the Raspberry Pi platform
 
+dtb-$(CONFIG_ARCH_BCM2835) += overlay_map.dtb
+
 dtbo-$(CONFIG_ARCH_BCM2835) += \
 	act-led.dtbo \
 	adau1977-adc.dtbo \

arch/arm/boot/dts/overlays/overlay_map.dts

@@ -0,0 +1,71 @@
+/dts-v1/;
+
+/ {
+	i2c3 {
+		bcm2711;
+	};
+
+	i2c4 {
+		bcm2711;
+	};
+
+	i2c5 {
+		bcm2711;
+	};
+
+	i2c6 {
+		bcm2711;
+	};
+
+	rpivid-v4l2 {
+		bcm2711;
+	};
+
+	spi3-1cs {
+		bcm2711;
+	};
+
+	spi3-2cs {
+		bcm2711;
+	};
+
+	spi4-1cs {
+		bcm2711;
+	};
+
+	spi4-2cs {
+		bcm2711;
+	};
+
+	spi5-1cs {
+		bcm2711;
+	};
+
+	spi5-2cs {
+		bcm2711;
+	};
+
+	spi6-1cs {
+		bcm2711;
+	};
+
+	spi6-2cs {
+		bcm2711;
+	};
+
+	uart2 {
+		bcm2711;
+	};
+
+	uart3 {
+		bcm2711;
+	};
+
+	uart4 {
+		bcm2711;
+	};
+
+	uart5 {
+		bcm2711;
+	};
+};