ARM: dts: marzen: Enable SCIF_CLK frequency and pins

Add and enable 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.

This increases the range and accuracy of supported baud rates.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7779-marzen.dts

@@ -165,6 +165,9 @@ &tmu0 {
 };
 
 &pfc {
+	pinctrl-0 = <&scif_clk_pins>;
+	pinctrl-names = "default";
+
 	du_pins: du {
 		du0 {
 			renesas,groups = "du0_rgb888", "du0_sync_1", "du0_clk_out_0";
@@ -176,6 +179,11 @@ du1 {
 		};
 	};
 
+	scif_clk_pins: scif_clk {
+		renesas,groups = "scif_clk_b";
+		renesas,function = "scif_clk";
+	};
+
 	ethernet_pins: ethernet {
 		intc {
 			renesas,groups = "intc_irq1_b";
@@ -222,6 +230,11 @@ &scif4 {
 	status = "okay";
 };
 
+&scif_clk {
+	clock-frequency = <14745600>;
+	status = "okay";
+};
+
 &sdhi0 {
 	pinctrl-0 = <&sdhi0_pins>;
 	pinctrl-names = "default";