ARM: dts: aspeed: ast2600-evb: Enable GFX device

Enable the GFX device with a framebuffer memory region.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NTommy Haung <tommy_huang@aspeedtech.com>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20220302024930.18758-3-tommy_huang@aspeedtech.comSigned-off-by: NJoel Stanley <joel@jms.id.au>

arch/arm/boot/dts/aspeed-ast2600-evb.dts

@@ -34,6 +34,13 @@
 			compatible = "shared-dma-pool";
 			reusable;
 		};
+
+		gfx_memory: framebuffer {
+			size = <0x01000000>;
+			alignment = <0x01000000>;
+			compatible = "shared-dma-pool";
+			reusable;
+		};
 	};
 
 	vcc_sdhci0: regulator-vcc-sdhci0 {
@@ -323,3 +330,8 @@
 	status = "okay";
 	memory-region = <&video_engine_memory>;
 };
+
+&gfx {
+	status = "okay";
+	memory-region = <&gfx_memory>;
+};