x86, Kconfig: Move PARAVIRT_DEBUG into the paravirt menu

This should be under the PARAVIRT_GUEST menu.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1362428421-9244-2-git-send-email-bp@alien8.de


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>