Consolidate cflags that are set on all devices

Move cflags that are set on all devices to deviceGlobalCflags:
-fno-canonical-system-headers
-ffunction-sections
-funwind-tables
-fstack-protector-strong
-Wa,--noexecstack
-D_FORTIFY_SOURCE=2
-Wstrict-aliasing=2
-Werror=format-security

Bug: 68855788
Test: m checkbuild
Change-Id: Iefec689fdd2749013d0cc003b3abec674a85fb74

cc/config/x86_device.go

@@ -22,18 +22,10 @@ import (
 
 var (
 	x86Cflags = []string{
-		"-Wa,--noexecstack",
-		"-Werror=format-security",
-		"-D_FORTIFY_SOURCE=2",
-		"-Wstrict-aliasing=2",
-		"-ffunction-sections",
 		"-finline-functions",
 		"-finline-limit=300",
 		"-fno-short-enums",
 		"-funswitch-loops",
-		"-funwind-tables",
-		"-fstack-protector-strong",
-		"-fno-canonical-system-headers",
 	}
 
 	x86ClangCflags = append(x86Cflags, []string{