tty: con3215, remove tasklet for tty_wakeup

tty: con3215, remove tasklet for tty_wakeup

tty_wakeup is safe to be called from all contexts. No need to schedule
a tasklet for that. Let us call it directly like in other drivers.

And delete the tasklet completely.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: linux-s390@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-18-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>