drm/udl: fix control-message timeout

USB control-message timeouts are specified in milliseconds and should
specifically not vary with CONFIG_HZ.

Fixes: 5320918b ("drm/udl: initial UDL driver (v4)")
Cc: stable@vger.kernel.org      # 3.4
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211025115353.5089-1-johan@kernel.org