i8042prt fails when IRP_MN_START_DEVICE sent to it

i8042prt driver fails the initialization if IRP_MN_START_DEVICE is sent to the stack before kbdclass or mouclass is attached. The handler contains dead code, and is broken in general.
(after kbdclass or mouclass is attached, IRP_MN_START_DEVICE is not sent to the driver at all)

Needs refactoring