Hi,

Current implementation of memory-mapped i8042 controller is atm 
implemented with an interface shift (it_shift) parameter, like most all 
memory-mapped devices in Qemu.
However, this isn't suitable for MIPS Magnum, where i8042 controller is 
at 0x80005000 up to 0x80005fff.

Thomas Bogendoerfer (from #mipslinux) tested the behaviour of a real 
machine, and found that odd addresses are for status/command register, 
and even addresses for data register.

Attached patch implements this behaviour by replacing the it_shift 
parameter by a mask one.
Incidentally, keyboard now works on OpenBSD 2.3, which accesses i8042 
controller at 0x80005060 and 0x80005061.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>

Changes since v1:
- updated to qemu svn

Hervé