ARM: dts: keystone: fix netcp's clocks definitions

The clocks tree for Keystone 2 NTCP devices should be
defined as following:
[refclk] - board dependent
|- <papllclk> - PLL clock
|- <paclk13> - fixed factor clock div=3 mul=1
|- <clkpa> - gated clock
|- <clkcpgmac> - gated clock
|- <clksa> - gated clock

Hence, update Keystone 2 DT to follow HW specification.

Signed-off-by: WingMan Kwok <[e-mail]>
Signed-off-by: Grygorii Strashko <[e-mail]>
Signed-off-by: Santosh Shilimkar <[e-mail]>

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

···
 		#clock-cells = <0>;
 		compatible = "ti,keystone,pll-clock";
 		clocks = <&refclkpass>;
-		clock-output-names = "pa-pll-clk";
+		clock-output-names = "papllclk";
 		reg = <0x02620358 4>;
 		reg-names = "control";
 	};

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

···
 		#clock-cells = <0>;
 		compatible = "ti,keystone,pll-clock";
 		clocks = <&refclkpass>;
-		clock-output-names = "pa-pll-clk";
+		clock-output-names = "papllclk";
 		reg = <0x02620358 4>;
 		reg-names = "control";
 	};

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

···
 		#clock-cells = <0>;
 		compatible = "ti,keystone,pll-clock";
 		clocks = <&refclksys>;
-		clock-output-names = "pa-pll-clk";
+		clock-output-names = "papllclk";
 		reg = <0x02620358 4>;
 		reg-names = "control";
 	};

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

···
 	clkpa: clkpa {
 		#clock-cells = <0>;
 		compatible = "ti,keystone,psc-clock";
-		clocks = <&chipclk16>;
+		clocks = <&paclk13>;
 		clock-output-names = "pa";
 		reg = <0x0235001c 0xb00>, <0x02350008 0x400>;
 		reg-names = "control", "domain";