Convert the driver to standard spilt model arch-specific code registers
platform device to which driver code can bind later.

Also request IRQ immediately upon binding to the device instead of doing
this when serio port is being opened.
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>