Move compiler.h to commonlib

Its spreading copies got out of sync. And as it is not a standard header
but used in commonlib code, it belongs into commonlib. While we are at
it, always include it via GCC's `-include` switch.

Some Windows and BSD quirk handling went into the util copies. We always
guard from redefinitions now to prevent further issues.

Change-Id: I850414e6db1d799dce71ff2dc044e6a000ad2552
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/28927
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/cpu/amd/mtrr.h

@@ -38,7 +38,6 @@
 
 #if !defined(__PRE_RAM__) && !defined(__ASSEMBLER__)
 
-#include <compiler.h>
 #include <cpu/x86/msr.h>
 
 void amd_setup_mtrrs(void);