x86, realmode: Move trampoline_*.S early in the link order

Move trampoline_*.S earlier in the link order so it ends up being
first in the text segment; since the SIPI vector requires 4K alignment
it otherwise ends up padding the .text segment with that much
completely unnecessarily.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-16-git-send-email-jarkko.sakkinen@intel.com