x86/devicetable: Move x86 specific macro out of generic code

There is no reason that this gunk is in a generic header file. The wildcard
defines need to stay as they are required by file2alias.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lkml.kernel.org/r/20200320131508.736205164@linutronix.de