x86_64: vdso.lds in arch/x86_64/vdso/.gitignore

Create arch/x86_64/vdso/.gitignore and put vdso.lds into it.
Signed-off-by: NPete Zaitcev <zaitcev@redhat.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/x86_64/vdso/.gitignore

+vdso.lds