initscripts: mask initscripts from systemd

Many of the init scripts in here will do nasty things if systemd decides to run
them.  Mask the obviously bad ones so that systemd won't attempt to invoke them
if initscripts is installed with systemd.

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
systemd-serialgetty: Update to match version in recent systemd

Whilst debugging other issues I noticed this was out of sync with the code
in systemd itself. This brings things back into sync and shouldn't hurt
anything.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>