ARM: dts: mmp2: specify reg-shift for the UARTs

This makes the 8250_of driver happy. There are two more drivers in the
tree that bind to mrvl,mmp-uart compatibles: pxa and 8250_pxa and
neither of them requires the reg-shift property, assuming it's always 2.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Pavel Machek <pavel@ucw.cz>

arch/arm/boot/dts/mmp2.dtsi

@@ -214,6 +214,7 @@ uart1: uart@d4030000 {
 				interrupts = <27>;
 				clocks = <&soc_clocks MMP2_CLK_UART0>;
 				resets = <&soc_clocks MMP2_CLK_UART0>;
+				reg-shift = <2>;
 				status = "disabled";
 			};
 
@@ -223,6 +224,7 @@ uart2: uart@d4017000 {
 				interrupts = <28>;
 				clocks = <&soc_clocks MMP2_CLK_UART1>;
 				resets = <&soc_clocks MMP2_CLK_UART1>;
+				reg-shift = <2>;
 				status = "disabled";
 			};
 
@@ -232,6 +234,7 @@ uart3: uart@d4018000 {
 				interrupts = <24>;
 				clocks = <&soc_clocks MMP2_CLK_UART2>;
 				resets = <&soc_clocks MMP2_CLK_UART2>;
+				reg-shift = <2>;
 				status = "disabled";
 			};
 
@@ -241,6 +244,7 @@ uart4: uart@d4016000 {
 				interrupts = <46>;
 				clocks = <&soc_clocks MMP2_CLK_UART3>;
 				resets = <&soc_clocks MMP2_CLK_UART3>;
+				reg-shift = <2>;
 				status = "disabled";
 			};