drm/i915: Copy default modparams to mock i915_device

Since we use the module parameters stored inside the drm_i915_device
itself, we need to ensure the mock i915_device also sets up the right
defaults.

Fixes: 8a25c4be58 ("drm/i915/params: switch to device specific parameters")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200728150600.4509-1-chris@chris-wilson.co.uk
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit 98ef067453)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/selftests/mock_gem_device.c

@@ -78,6 +78,7 @@ static void mock_device_release(struct drm_device *dev)
 	drm_mode_config_cleanup(&i915->drm);
 
 out:
+	i915_params_free(&i915->params);
 	put_device(&i915->drm.pdev->dev);
 	i915->drm.pdev = NULL;
 }
@@ -165,6 +166,8 @@ struct drm_i915_private *mock_gem_device(void)
 	i915->drm.pdev = pdev;
 	drmm_add_final_kfree(&i915->drm, i915);
 
+	i915_params_copy(&i915->params, &i915_modparams);
+
 	intel_runtime_pm_init_early(&i915->runtime_pm);
 
 	/* Using the global GTT may ask questions about KMS users, so prepare */