vt: fix the keyboard/led locking

We touch the LED from both keyboard callback and direct paths. In
one case we've got the lock held way up the call chain and in the
other we haven't. This leads to complete insanity so fix it by giving
the LED bits their own lock.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>