drm/i915: Fix type of timeout_ms parameter in intel_wait_for_register_fw()

drm/i915: Fix type of timeout_ms parameter in intel_wait_for_register_fw()

There is no need to specify timeout as unsigned long since this parameter
will be consumed by usecs_to_jiffies() which expects unsigned int only.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170407133212.174608-1-michal.wajdeczko@intel.com
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>