arm64: dts: mediatek: mt8516: add support for APDMA

Add support the APDMA IP on MT8516. APDMA is a DMA controller
for UARTs.
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Link: https://lore.kernel.org/r/20201209114736.70625-2-fparent@baylibre.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm64/boot/dts/mediatek/mt8516.dtsi

@@ -276,6 +276,27 @@ gic: interrupt-controller@10310000 {
 				(GIC_CPU_MASK_SIMPLE(4) | IRQ_TYPE_LEVEL_HIGH)>;
 		};
 
+		apdma: dma-controller@11000480 {
+			compatible = "mediatek,mt8516-uart-dma",
+				     "mediatek,mt6577-uart-dma";
+			reg = <0 0x11000480 0 0x80>,
+			      <0 0x11000500 0 0x80>,
+			      <0 0x11000580 0 0x80>,
+			      <0 0x11000600 0 0x80>,
+			      <0 0x11000980 0 0x80>,
+			      <0 0x11000a00 0 0x80>;
+			interrupts = <GIC_SPI 96 IRQ_TYPE_LEVEL_LOW>,
+				     <GIC_SPI 97 IRQ_TYPE_LEVEL_LOW>,
+				     <GIC_SPI 98 IRQ_TYPE_LEVEL_LOW>,
+				     <GIC_SPI 99 IRQ_TYPE_LEVEL_LOW>,
+				     <GIC_SPI 100 IRQ_TYPE_LEVEL_LOW>,
+				     <GIC_SPI 101 IRQ_TYPE_LEVEL_LOW>;
+			dma-requests = <6>;
+			clocks = <&topckgen CLK_TOP_APDMA>;
+			clock-names = "apdma";
+			#dma-cells = <1>;
+		};
+
 		uart0: serial@11005000 {
 			compatible = "mediatek,mt8516-uart",
 				     "mediatek,mt6577-uart";
@@ -284,6 +305,9 @@ uart0: serial@11005000 {
 			clocks = <&topckgen CLK_TOP_UART0_SEL>,
 				 <&topckgen CLK_TOP_UART0>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 0
+				&apdma 1>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};
 
@@ -295,6 +319,9 @@ uart1: serial@11006000 {
 			clocks = <&topckgen CLK_TOP_UART1_SEL>,
 				 <&topckgen CLK_TOP_UART1>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 2
+				&apdma 3>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};
 
@@ -306,6 +333,9 @@ uart2: serial@11007000 {
 			clocks = <&topckgen CLK_TOP_UART2_SEL>,
 				 <&topckgen CLK_TOP_UART2>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 4
+				&apdma 5>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};