ARM: dts: at91: sama5d3: switch to new sckc bindings

Remove the child nodes of the sckc as they are not necessary anymore.

Also, switch to the new atmel,sama5d3-sckc compatible string to use the
proper startup time for the RC oscillator (500 µs instead of 75).
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

arch/arm/boot/dts/at91-wb50n.dtsi

@@ -42,7 +42,7 @@ &main_xtal {
 	clock-frequency = <12000000>;
 };
 
-&slow_osc {
+&clk32k {
 	atmel,osc-bypass;
 };
 

arch/arm/boot/dts/sama5d3.dtsi

@@ -1372,30 +1372,11 @@ watchdog: watchdog@fffffe40 {
 				status = "disabled";
 			};
 
-			sckc@fffffe50 {
-				compatible = "atmel,at91sam9x5-sckc";
+			clk32k: sckc@fffffe50 {
+				compatible = "atmel,sama5d3-sckc";
 				reg = <0xfffffe50 0x4>;
-
-				slow_rc_osc: slow_rc_osc {
-					compatible = "atmel,at91sam9x5-clk-slow-rc-osc";
-					#clock-cells = <0>;
-					clock-frequency = <32768>;
-					clock-accuracy = <50000000>;
-					atmel,startup-time-usec = <75>;
-				};
-
-				slow_osc: slow_osc {
-					compatible = "atmel,at91sam9x5-clk-slow-osc";
-					#clock-cells = <0>;
-					clocks = <&slow_xtal>;
-					atmel,startup-time-usec = <1200000>;
-				};
-
-				clk32k: slowck {
-					compatible = "atmel,at91sam9x5-clk-slow";
-					#clock-cells = <0>;
-					clocks = <&slow_rc_osc &slow_osc>;
-				};
+				clocks = <&slow_xtal>;
+				#clock-cells = <0>;
 			};
 
 			rtc@fffffeb0 {