drm/kunit: fix drm_kunit_helpers.h kernel-doc

s/_features/_feat/ to match code.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/f909224abc8d542a89b66b957a32f152f42e9bba.1709749576.git.jani.nikula@intel.com

include/drm/drm_kunit_helpers.h

@@ -75,7 +75,7 @@ __drm_kunit_helper_alloc_drm_device(struct kunit *test,
  * @_dev: The parent device object
  * @_type: the type of the struct which contains struct &drm_device
  * @_member: the name of the &drm_device within @_type.
- * @_features: Mocked DRM device driver features
+ * @_feat: Mocked DRM device driver features
  *
  * This function creates a struct &drm_driver and will create a struct
  * &drm_device from @_dev and that driver.