drm/i915/params: fix i915.reset module param type

The reset member in i915_params was previously changed to unsigned, but
this failed to change the actual module parameter.

Fixes: aae970d8

 ("drm/i915: Mark i915.reset as unsigned")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200602151126.25626-1-jani.nikula@intel.com
(cherry picked from commit 34becfdb

)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>