ARM: dts: keystone: fix dt bindings to use post div register for mainpll

All of the keystone devices have a separate register to hold post
divider value for main pll clock. Currently the fixed-postdiv
value used for k2hk/l/e SoCs works by sheer luck as u-boot happens to
use a value of 2 for this. Now that we have fixed this in the pll
clock driver change the dt bindings for the same.

Signed-off-by: Murali Karicheri <[e-mail]>
Acked-by: Santosh Shilimkar <[e-mail]>
Signed-off-by: Olof Johansson <[e-mail]>

arch/arm/boot/dts/k2e-clocks.dtsi

···
 		#clock-cells = <0>;
 		compatible = "ti,keystone,main-pll-clock";
 		clocks = <&refclksys>;
-		reg = <0x02620350 4>, <0x02310110 4>;
-		reg-names = "control", "multiplier";
-		fixed-postdiv = <2>;
+		reg = <0x02620350 4>, <0x02310110 4>, <0x02310108 4>;
+		reg-names = "control", "multiplier", "post-divider";
 	};
 
 	papllclk: papllclk@2620358 {

arch/arm/boot/dts/k2hk-clocks.dtsi

···
 		#clock-cells = <0>;
 		compatible = "ti,keystone,main-pll-clock";
 		clocks = <&refclksys>;
-		reg = <0x02620350 4>, <0x02310110 4>;
-		reg-names = "control", "multiplier";
-		fixed-postdiv = <2>;
+		reg = <0x02620350 4>, <0x02310110 4>, <0x02310108 4>;
+		reg-names = "control", "multiplier", "post-divider";
 	};
 
 	papllclk: papllclk@2620358 {

arch/arm/boot/dts/k2l-clocks.dtsi

···
 		#clock-cells = <0>;
 		compatible = "ti,keystone,main-pll-clock";
 		clocks = <&refclksys>;
-		reg = <0x02620350 4>, <0x02310110 4>;
-		reg-names = "control", "multiplier";
-		fixed-postdiv = <2>;
+		reg = <0x02620350 4>, <0x02310110 4>, <0x02310108 4>;
+		reg-names = "control", "multiplier", "post-divider";
 	};
 
 	papllclk: papllclk@2620358 {