x86: Make RW unused section labels unique

BUG=none
TEST=check fmap on generated binary for unique names

Change-Id: I7d35822153627bdbad3417e70febe0b8924937e9
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/18436
diff --git a/board/chromebook-x86/coreboot/flashmap-8mb.dtsi b/board/chromebook-x86/coreboot/flashmap-8mb.dtsi
index 70a6553..681b612 100644
--- a/board/chromebook-x86/coreboot/flashmap-8mb.dtsi
+++ b/board/chromebook-x86/coreboot/flashmap-8mb.dtsi
@@ -152,7 +152,7 @@
 			type = "blobstring fwid";
 		};
 		rw-a-unused@0 {
-			label = "rw-unused";
+			label = "rw-unused-a";
 			reg = <0x00290000 0x00070000>;
 			type = "wiped";
 			wipe-value = [ff];
@@ -192,7 +192,7 @@
 			type = "blobstring fwid";
 		};
 		rw-b-unused@0 {
-			label = "rw-unused";
+			label = "rw-unused-b";
 			reg = <0x00390000 0x00070000>;
 			type = "wiped";
 			wipe-value = [ff];