vdso / vsycall create .so.dbg files now.
Add *.so.dbg to the main .ignore file

Exclude the compile time created boot directory in arch/x86_64 as well
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch:
- makes .gitignore files visible to git
- makes arch/x86/kernel/vsyscall_32.lds and arch/i386/boot invisible
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>