kexec man page change for debug option

In commit 28d4ab53, the arch-specific --debug are moved to
generic place, but the relevant description was not updated
accordingly in man page. Here change it.

Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
1 file changed