xtensa: fix DTC warning unit_address_format

DTC issues the following warnings when building xtfpga device trees:

 /soc/flash@00000000/partition@0x0: unit name should not have leading "0x"
 /soc/flash@00000000/partition@0x6000000: unit name should not have leading "0x"
 /soc/flash@00000000/partition@0x6800000: unit name should not have leading "0x"
 /soc/flash@00000000/partition@0x7fe0000: unit name should not have leading "0x"

Drop leading 0x from flash partition unit names.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Author: jcmvbkbc

arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi

@@ -8,19 +8,19 @@
 			reg = <0x00000000 0x08000000>;
 			bank-width = <2>;
 			device-width = <2>;
-			partition@0x0 {
+			partition@0 {
 				label = "data";
 				reg = <0x00000000 0x06000000>;
 			};
-			partition@0x6000000 {
+			partition@6000000 {
 				label = "boot loader area";
 				reg = <0x06000000 0x00800000>;
 			};
-			partition@0x6800000 {
+			partition@6800000 {
 				label = "kernel image";
 				reg = <0x06800000 0x017e0000>;
 			};
-			partition@0x7fe0000 {
+			partition@7fe0000 {
 				label = "boot environment";
 				reg = <0x07fe0000 0x00020000>;
 			};

arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi

@@ -8,19 +8,19 @@
 			reg = <0x08000000 0x01000000>;
 			bank-width = <2>;
 			device-width = <2>;
-			partition@0x0 {
+			partition@0 {
 				label = "boot loader area";
 				reg = <0x00000000 0x00400000>;
 			};
-			partition@0x400000 {
+			partition@400000 {
 				label = "kernel image";
 				reg = <0x00400000 0x00600000>;
 			};
-			partition@0xa00000 {
+			partition@a00000 {
 				label = "data";
 				reg = <0x00a00000 0x005e0000>;
 			};
-			partition@0xfe0000 {
+			partition@fe0000 {
 				label = "boot environment";
 				reg = <0x00fe0000 0x00020000>;
 			};

arch/xtensa/boot/dts/xtfpga-flash-4m.dtsi

@@ -8,11 +8,11 @@
 			reg = <0x08000000 0x00400000>;
 			bank-width = <2>;
 			device-width = <2>;
-			partition@0x0 {
+			partition@0 {
 				label = "boot loader area";
 				reg = <0x00000000 0x003f0000>;
 			};
-			partition@0x3f0000 {
+			partition@3f0000 {
 				label = "boot environment";
 				reg = <0x003f0000 0x00010000>;
 			};