Char: moxa, do not touch NORMAL_ACTIVE bit

The bit is set in tty_port_block_til_ready (via moxa_open) and unset
in tty_port_close (via moxa_close). No need to pin it in the driver.

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