ARM: at91: sama5d3: add usart dma configurations

Add the DMA configuration for USARTs mainly because it is not obvious to
add the FIFO flag which is needed for rx.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/boot/dts/sama5d3.dtsi

@@ -177,6 +177,9 @@ usart0: serial@f001c000 {
 				compatible = "atmel,at91sam9260-usart";
 				reg = <0xf001c000 0x100>;
 				interrupts = <12 IRQ_TYPE_LEVEL_HIGH 5>;
+				dmas = <&dma0 2 AT91_DMA_CFG_PER_ID(3)>,
+				       <&dma0 2 (AT91_DMA_CFG_PER_ID(4) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart0>;
 				clocks = <&usart0_clk>;
@@ -188,6 +191,9 @@ usart1: serial@f0020000 {
 				compatible = "atmel,at91sam9260-usart";
 				reg = <0xf0020000 0x100>;
 				interrupts = <13 IRQ_TYPE_LEVEL_HIGH 5>;
+				dmas = <&dma0 2 AT91_DMA_CFG_PER_ID(5)>,
+				       <&dma0 2 (AT91_DMA_CFG_PER_ID(6) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart1>;
 				clocks = <&usart1_clk>;
@@ -333,6 +339,9 @@ usart2: serial@f8020000 {
 				compatible = "atmel,at91sam9260-usart";
 				reg = <0xf8020000 0x100>;
 				interrupts = <14 IRQ_TYPE_LEVEL_HIGH 5>;
+				dmas = <&dma1 2 AT91_DMA_CFG_PER_ID(7)>,
+				       <&dma1 2 (AT91_DMA_CFG_PER_ID(8) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart2>;
 				clocks = <&usart2_clk>;
@@ -344,6 +353,9 @@ usart3: serial@f8024000 {
 				compatible = "atmel,at91sam9260-usart";
 				reg = <0xf8024000 0x100>;
 				interrupts = <15 IRQ_TYPE_LEVEL_HIGH 5>;
+				dmas = <&dma1 2 AT91_DMA_CFG_PER_ID(9)>,
+				       <&dma1 2 (AT91_DMA_CFG_PER_ID(10) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart3>;
 				clocks = <&usart3_clk>;
@@ -412,6 +424,9 @@ dbgu: serial@ffffee00 {
 				compatible = "atmel,at91sam9260-usart";
 				reg = <0xffffee00 0x200>;
 				interrupts = <2 IRQ_TYPE_LEVEL_HIGH 7>;
+				dmas = <&dma1 2 AT91_DMA_CFG_PER_ID(13)>,
+				       <&dma1 2 (AT91_DMA_CFG_PER_ID(14) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_dbgu>;
 				clocks = <&dbgu_clk>;