ARM: dts: da850: Add ti,da830-uart compatible for serial ports

TI DA8xx/OMAPL13x/AM17xx/AM18xx SoCs have extra UART registers beyond
the standard 8250 registers, so we need a new compatible string to
indicate this. Also, at least one of these registers uses the full 32
bits, so we need to specify reg-io-width in addition to reg-shift.

"ns16550a" is left in the compatible specification since it does work
as long as the bootloader configures the SoC UART power management
registers.

Signed-off-by: David Lechner <[e-mail]>
Signed-off-by: Sekhar Nori <[e-mail]>

arch/arm/boot/dts/da850.dtsi

···
 			interrupt-names = "edm3_tcerrint";
 		};
 		serial0: serial@42000 {
-			compatible = "ns16550a";
+			compatible = "ti,da830-uart", "ns16550a";
 			reg = <0x42000 0x100>;
+			reg-io-width = <4>;
 			reg-shift = <2>;
 			interrupts = <25>;
 			status = "disabled";
 		};
 		serial1: serial@10c000 {
-			compatible = "ns16550a";
+			compatible = "ti,da830-uart", "ns16550a";
 			reg = <0x10c000 0x100>;
+			reg-io-width = <4>;
 			reg-shift = <2>;
 			interrupts = <53>;
 			status = "disabled";
 		};
 		serial2: serial@10d000 {
-			compatible = "ns16550a";
+			compatible = "ti,da830-uart", "ns16550a";
 			reg = <0x10d000 0x100>;
+			reg-io-width = <4>;
 			reg-shift = <2>;
 			interrupts = <61>;
 			status = "disabled";