macbook11: Fix typo

Change-Id: Iddd4d99af7e1c70384f13f18d785f491c47c7617
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/6712
Tested-by: build bot (Jenkins)
Reviewed-by: Francis Rowe <info@gluglug.org.uk>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>