ARM: dts: r8a7779: Use R-Car GPIO Gen1 fallback compat string

Use newly added R-Car GPIO Gen1 fallback compat string
in place of now deprecated non-generation specific
R-Car GPIO fallback compat string in DT of r8a7779 SoC.

As the driver does not match on "renesas,gpio-r8a7779" there
are some run-time considerations for this patch:

* When a resulting DTB is used with kernels newer than v4.14 this should
  not have any run-time effect as renesas,rcar-gen1-gpio is matched by the
  driver since commit dbd1dad2 ("gpio: rcar: add gen[123] fallback
  compatibility strings")

* However, when used with older kernels GPIO will be disabled as
  no compat string match will be made by the driver.

The regression documented above for the new DTB with old kernel case
is acceptable in my opinion.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm/boot/dts/r8a7779.dtsi

@@ -76,7 +76,7 @@ timer@f0000600 {
 	};
 
 	gpio0: gpio@ffc40000 {
-		compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+		compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
 		reg = <0xffc40000 0x2c>;
 		interrupts = <GIC_SPI 141 IRQ_TYPE_LEVEL_HIGH>;
 		#gpio-cells = <2>;
@@ -87,7 +87,7 @@ gpio0: gpio@ffc40000 {
 	};
 
 	gpio1: gpio@ffc41000 {
-		compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+		compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
 		reg = <0xffc41000 0x2c>;
 		interrupts = <GIC_SPI 142 IRQ_TYPE_LEVEL_HIGH>;
 		#gpio-cells = <2>;
@@ -98,7 +98,7 @@ gpio1: gpio@ffc41000 {
 	};
 
 	gpio2: gpio@ffc42000 {
-		compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+		compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
 		reg = <0xffc42000 0x2c>;
 		interrupts = <GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>;
 		#gpio-cells = <2>;
@@ -109,7 +109,7 @@ gpio2: gpio@ffc42000 {
 	};
 
 	gpio3: gpio@ffc43000 {
-		compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+		compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
 		reg = <0xffc43000 0x2c>;
 		interrupts = <GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>;
 		#gpio-cells = <2>;
@@ -120,7 +120,7 @@ gpio3: gpio@ffc43000 {
 	};
 
 	gpio4: gpio@ffc44000 {
-		compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+		compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
 		reg = <0xffc44000 0x2c>;
 		interrupts = <GIC_SPI 145 IRQ_TYPE_LEVEL_HIGH>;
 		#gpio-cells = <2>;
@@ -131,7 +131,7 @@ gpio4: gpio@ffc44000 {
 	};
 
 	gpio5: gpio@ffc45000 {
-		compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+		compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
 		reg = <0xffc45000 0x2c>;
 		interrupts = <GIC_SPI 146 IRQ_TYPE_LEVEL_HIGH>;
 		#gpio-cells = <2>;
@@ -142,7 +142,7 @@ gpio5: gpio@ffc45000 {
 	};
 
 	gpio6: gpio@ffc46000 {
-		compatible = "renesas,gpio-r8a7779", "renesas,gpio-rcar";
+		compatible = "renesas,gpio-r8a7779", "renesas,rcar-gen1-gpio";
 		reg = <0xffc46000 0x2c>;
 		interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>;
 		#gpio-cells = <2>;