tty: Revert the tty locking series, it needs more work

tty: Revert the tty locking series, it needs more work

This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is 7e450ea394aa ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  f5ec3cb93fd7 - tty: add lockdep annotations
  b3660aeb466a - tty: fix ldisc lock inversion trace
  c7803fb3f92e - pty: Fix lock inversion
  91e3c4690c42 - tty: drop the pty lock during hangup
  dd7535374014 - tty/amiserial: Add missing argument for tty_unlock()
  7c1a58259a7e - cris: fix missing tty arg in wait_event_interruptible_tty call
  7e450ea394aa - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>