ARM: shmobile: r8a7790: Add IRQC clock to device tree

Link the external IRQ controller irqc0 to the IRQC module clock, so it
can be power managed using that clock.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7790.dtsi

@@ -252,6 +252,7 @@
 			     <0 1 IRQ_TYPE_LEVEL_HIGH>,
 			     <0 2 IRQ_TYPE_LEVEL_HIGH>,
 			     <0 3 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&mstp4_clks R8A7790_CLK_IRQC>;
 	};
 
 	dmac0: dma-controller@e6700000 {
@@ -1158,6 +1159,14 @@
 				"iic0", "pciec", "iic1", "ssusb", "cmt1",
 				"usbdmac0", "usbdmac1";
 		};
+		mstp4_clks: mstp4_clks@e6150140 {
+			compatible = "renesas,r8a7790-mstp-clocks", "renesas,cpg-mstp-clocks";
+			reg = <0 0xe6150140 0 4>, <0 0xe615004c 0 4>;
+			clocks = <&cp_clk>;
+			#clock-cells = <1>;
+			clock-indices = <R8A7790_CLK_IRQC>;
+			clock-output-names = "irqc";
+		};
 		mstp5_clks: mstp5_clks@e6150144 {
 			compatible = "renesas,r8a7790-mstp-clocks", "renesas,cpg-mstp-clocks";
 			reg = <0 0xe6150144 0 4>, <0 0xe615003c 0 4>;

include/dt-bindings/clock/r8a7790-clock.h

@@ -79,6 +79,9 @@
 #define R8A7790_CLK_USBDMAC0		30
 #define R8A7790_CLK_USBDMAC1		31
 
+/* MSTP4 */
+#define R8A7790_CLK_IRQC		7
+
 /* MSTP5 */
 #define R8A7790_CLK_AUDIO_DMAC1		1
 #define R8A7790_CLK_AUDIO_DMAC0		2