Move -fomit-frame-pointer to armCflags

-fomit-frame-pointer was specified twice, once for arm and once for
thumb.  Move it to the shared cflags.

Bug: 68855788
Test: m checkbuild
Change-Id: Iab1299c247808f1a2542b468084600b7c32996e8

cc/config/arm_device.go

@@ -38,6 +38,8 @@ var (
 		"-fgcse-after-reload",
 		"-frerun-cse-after-loop",
 		"-frename-registers",
+
+		"-fomit-frame-pointer",
 	}
 
 	armCppflags = []string{
@@ -51,7 +53,6 @@ var (
 	}
 
 	armArmCflags = []string{
-		"-fomit-frame-pointer",
 		"-fstrict-aliasing",
 		"-funswitch-loops",
 	}
@@ -59,7 +60,6 @@ var (
 	armThumbCflags = []string{
 		"-mthumb",
 		"-Os",
-		"-fomit-frame-pointer",
 	}
 
 	armArchVariantCflags = map[string][]string{