arm64: dts: m3ulcb: enable SCIF clk and pins

This enables the external crystal for the SCIF_CLK and its pinctrl, to
be used by the Baud Rate Generator for External Clock (BRG) on (H)SCIF.
Signed-off-by: NVladimir Barinov <vladimir.barinov@cogentembedded.com>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dts

@@ -37,10 +37,18 @@
 };
 
 &pfc {
+	pinctrl-0 = <&scif_clk_pins>;
+	pinctrl-names = "default";
+
 	scif2_pins: scif2 {
 		groups = "scif2_data_a";
 		function = "scif2";
 	};
+
+	scif_clk_pins: scif_clk {
+		groups = "scif_clk_a";
+		function = "scif_clk";
+	};
 };
 
 &scif2 {
@@ -49,3 +57,8 @@
 
 	status = "okay";
 };
+
+&scif_clk {
+	clock-frequency = <14745600>;
+	status = "okay";
+};