arch/x86/kernel/.gitignore: Added vmlinux.lds to .gitignore file because it shouldn't be tracked.

Signed-off-by: NDaniel Guilak <daniel@danielguilak.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/.gitignore

 vsyscall.lds
 vsyscall_32.lds
+vmlinux.lds