ARC: [nsimosci] Enable ARC PGU on nSIM OSCI virtual platforms

With required ARC PGU updates that allow it to be used on simulation
platforms we may finally utilize ARC PGU in nSIM OSCI virtual platforms
with modern Linux kernels.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/arch/arc/boot/dts/nsimosci.dts b/arch/arc/boot/dts/nsimosci.dts
index b5b060a..37c416d 100644
--- a/arch/arc/boot/dts/nsimosci.dts
+++ b/arch/arc/boot/dts/nsimosci.dts
@@ -20,7 +20,7 @@
 		/* this is for console on PGU */
 		/* bootargs = "console=tty0 consoleblank=0"; */
 		/* this is for console on serial */
-		bootargs = "earlycon=uart8250,mmio32,0xf0000000,115200n8 console=tty0 console=ttyS0,115200n8 consoleblank=0 debug";
+		bootargs = "earlycon=uart8250,mmio32,0xf0000000,115200n8 console=tty0 console=ttyS0,115200n8 consoleblank=0 debug video=640x480-24";
 	};
 
 	aliases {
@@ -58,9 +58,17 @@
 			no-loopback-test = <1>;
 		};
 
-		pgu0: pgu@f9000000 {
-			compatible = "snps,arcpgufb";
+		pguclk: pguclk {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <25175000>;
+		};
+
+		pgu@f9000000 {
+			compatible = "snps,arcpgu";
 			reg = <0xf9000000 0x400>;
+			clocks = <&pguclk>;
+			clock-names = "pxlclk";
 		};
 
 		ps2: ps2@f9001000 {
diff --git a/arch/arc/boot/dts/nsimosci_hs.dts b/arch/arc/boot/dts/nsimosci_hs.dts
index 325e730..f2a22c4 100644
--- a/arch/arc/boot/dts/nsimosci_hs.dts
+++ b/arch/arc/boot/dts/nsimosci_hs.dts
@@ -20,7 +20,7 @@
 		/* this is for console on PGU */
 		/* bootargs = "console=tty0 consoleblank=0"; */
 		/* this is for console on serial */
-		bootargs = "earlycon=uart8250,mmio32,0xf0000000,115200n8 console=tty0 console=ttyS0,115200n8 consoleblank=0 debug";
+		bootargs = "earlycon=uart8250,mmio32,0xf0000000,115200n8 console=tty0 console=ttyS0,115200n8 consoleblank=0 debug video=640x480-24";
 	};
 
 	aliases {
@@ -58,9 +58,17 @@
 			no-loopback-test = <1>;
 		};
 
-		pgu0: pgu@f9000000 {
-			compatible = "snps,arcpgufb";
+		pguclk: pguclk {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <25175000>;
+		};
+
+		pgu@f9000000 {
+			compatible = "snps,arcpgu";
 			reg = <0xf9000000 0x400>;
+			clocks = <&pguclk>;
+			clock-names = "pxlclk";
 		};
 
 		ps2: ps2@f9001000 {
diff --git a/arch/arc/boot/dts/nsimosci_hs_idu.dts b/arch/arc/boot/dts/nsimosci_hs_idu.dts
index ee03d71..34457a5 100644
--- a/arch/arc/boot/dts/nsimosci_hs_idu.dts
+++ b/arch/arc/boot/dts/nsimosci_hs_idu.dts
@@ -18,7 +18,7 @@
 
 	chosen {
 		/* this is for console on serial */
-		bootargs = "earlycon=uart8250,mmio32,0xf0000000,115200n8 console=tty0 console=ttyS0,115200n8 consoleblan=0 debug";
+		bootargs = "earlycon=uart8250,mmio32,0xf0000000,115200n8 console=tty0 console=ttyS0,115200n8 consoleblan=0 debug video=640x480-24";
 	};
 
 	aliases {
@@ -77,9 +77,17 @@
 			no-loopback-test = <1>;
 		};
 
-		pgu0: pgu@f9000000 {
-			compatible = "snps,arcpgufb";
+		pguclk: pguclk {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <25175000>;
+		};
+
+		pgu@f9000000 {
+			compatible = "snps,arcpgu";
 			reg = <0xf9000000 0x400>;
+			clocks = <&pguclk>;
+			clock-names = "pxlclk";
 		};
 
 		ps2: ps2@f9001000 {