Input: gamecon - add rumble support for N64 pads

Add force-feedback support for N64 pads with rumble pak accessory installed.
Actually we do not check for the presence of rumble pad but simply assume it
is installed and expect the device to ignore FF commands if rumble pak is
missing.

Signed-off-by: Scott Moreau <oreaus@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>