ARM: dts: aspeed: Add aspeed-p2a-ctrl node

Add a node for the aspeed-p2a-ctrl module.  This node, when enabled will
disable the PCI-to-AHB bridge and then allow control of this bridge via
ioctls, and access via mmap.
Signed-off-by: Patrick Venture <venture@google.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/boot/dts/aspeed-g4.dtsi

@@ -165,6 +165,10 @@ pinctrl: pinctrl {
 					compatible = "aspeed,g4-pinctrl";
 				};
 
+				p2a: p2a-control {
+					compatible = "aspeed,ast2400-p2a-ctrl";
+					status = "disabled";
+				};
 			};
 
 			rng: hwrng@1e6e2078 {

arch/arm/boot/dts/aspeed-g5.dtsi

@@ -219,6 +219,11 @@ pinctrl: pinctrl {
 					aspeed,external-nodes = <&gfx &lhc>;
 
 				};
+
+				p2a: p2a-control {
+					compatible = "aspeed,ast2500-p2a-ctrl";
+					status = "disabled";
+				};
 			};
 
 			rng: hwrng@1e6e2078 {