tty: localise the lock

tty: localise the lock

The termios and other changes mean the other protections needed on the driver
tty arrays should be adequate. Turn it all back on.

This contains pieces folded in from the fixes made to the original patches

| From: Geert Uytterhoeven <[email protected]>	(fix m68k)
| From: Paul Gortmaker <[email protected]>	(fix cris)
| From: Jiri Kosina <[email protected]>			(lockdep)
| From: Eric Dumazet <[email protected]>		(lockdep)

Signed-off-by: Alan Cox <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>