[S390] 3270: lock dependency fixes

Lockdep found a problem with the lock order of the view lock and the
ccw device lock. raw3270_activate_view/raw3270_deactivate_view first
take the ccw device lock then call the activate/deactivate functions
of the view which take view lock. The update functions of the
con3270/tty3270 view will first take the view lock, then take the
ccw device lock. To fix this the activate/deactivate functions are
changed to avoid taking the view lock by moving the functions calls
that modify the 3270 output buffer to the update function which is
called by a timer.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>