tty: move obsolete and broken generic_serial drivers to drivers/staging/generic_serial/

As planned by Arnd Bergmann, this moves the following drivers to the
drivers/staging/generic_serial directory where they will be removed
after 2.6.41 if no one steps up to claim them.
	generic_serial
	rio
	ser_a2232
	sx
	vme_scc

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>