livepatch-build: Handle newly created object files

livepatch-build: Handle newly created object files

Up to now the livepatch-build ignores newly created object files.
When patch applies new .c file and augments its Makefile to build it
the resulting object file is not taken into account for final linking
step.

Such newly created object files can be detected by comparing patched/
and original/ directories and copied over to the output directory for
the final linking step.

Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
Reviewed-by: Andra-Irina Paraschiv <andraprs@amazon.com>
Reviewed-by: Bjoern Doebel <doebel@amazon.de>
Reviewed-by: Norbert Manthey <nmanthey@amazon.de>