xcompile: add support for x86-64

Add support for detecting an x86-64 cross compiler in xcompile.

Change-Id: Icd2c9af7903956216db1fd54902eab6da0fe3e21
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Signed-off-by: Scott Duplichan <scott@notabs.org>
Reviewed-on: http://review.coreboot.org/8669
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
1 file changed