pc: move port 92 stuff back to pc.c from pckbd.c

pc: move port 92 stuff back to pc.c from pckbd.c

956a3e6bb7386de48b642d4fee11f7f86a2fcf9a introduced a bug concerning
reset bit for port 92.

Since the keyboard output port and port 92 are not compatible anyway,
let's separate them.

Reported-by: Peter Lieven <pl@dlh.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
--
v2: added reset handler and VMState