dt-bindings: fpga: fpga-region: Convert to sugar syntax

Using overlay sugar syntax makes the DTS files easier to read (and
write).

While at it, fix two build issues:
  - "/dts-v1/" and "/plugin/" must be separate statements.
  - Add a missing closing curly brace.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Moritz Fischer <mdf@kernel.org>

Documentation/devicetree/bindings/fpga/fpga-region.txt

@@ -245,13 +245,10 @@ Base tree contains:
 
 Overlay contains:
 
-/dts-v1/ /plugin/;
-/ {
-	fragment@0 {
-		target = <&fpga_region0>;
-		#address-cells = <1>;
-		#size-cells = <1>;
-		__overlay__ {
+/dts-v1/;
+/plugin/;
+
+&fpga_region0 {
 	#address-cells = <1>;
 	#size-cells = <1>;
 
@@ -274,8 +271,6 @@ Overlay contains:
 		compatible = "altr,onchipmem-15.1";
 		reg = <0x0 0x10000>;
 	};
-		};
-	};
 };
 
 
@@ -371,13 +366,11 @@ Live Device Tree contains:
 	};
 
 DT Overlay contains:
-/dts-v1/ /plugin/;
-/ {
-fragment@0 {
-	target = <&fpga_region0>;
-	#address-cells = <1>;
-	#size-cells = <1>;
-	__overlay__ {
+
+/dts-v1/;
+/plugin/;
+
+&fpga_region0 {
 	#address-cells = <1>;
 	#size-cells = <1>;
 
@@ -390,7 +383,6 @@ fragment@0 {
 		#gpio-cells = <0x2>;
 		xlnx,gpio-width= <0x6>;
 	};
-	};
 };
 
 Device Tree Example: Full Reconfiguration to add PRR's
@@ -402,13 +394,11 @@ This example programs the FPGA to have two regions that can later be partially
 configured.  Each region has its own bridge in the FPGA fabric.
 
 DT Overlay contains:
-/dts-v1/ /plugin/;
-/ {
-	fragment@0 {
-		target = <&fpga_region0>;
-		#address-cells = <1>;
-		#size-cells = <1>;
-		__overlay__ {
+
+/dts-v1/;
+/plugin/;
+
+&fpga_region0 {
 	#address-cells = <1>;
 	#size-cells = <1>;
 
@@ -437,8 +427,6 @@ DT Overlay contains:
 			ranges;
 		};
 	};
-		};
-	};
 };
 
 Device Tree Example: Partial Reconfiguration
@@ -451,13 +439,10 @@ differences are that the FPGA is partially reconfigured due to the
 "partial-fpga-config" boolean and the only bridge that is controlled during
 programming is the FPGA based bridge of fpga_region1.
 
-/dts-v1/ /plugin/;
-/ {
-	fragment@0 {
-		target = <&fpga_region1>;
-		#address-cells = <1>;
-		#size-cells = <1>;
-		__overlay__ {
+/dts-v1/;
+/plugin/;
+
+&fpga_region1 {
 	#address-cells = <1>;
 	#size-cells = <1>;
 
@@ -472,8 +457,6 @@ programming is the FPGA based bridge of fpga_region1.
 		#gpio-cells = <0x2>;
 		gpio-controller;
 	};
-		};
-	};
 };
 
 Constraints