drm/i915/rps: store struct dma_fence in struct wait_rps_boost
Prefer the more generic pointer rather than i915 specific data
type. Also use dma_fence_put() for symmetry with the dma_fence_get()
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/950948ae6d3d5fbc4af3401ea77e609945b73a77.1763370931.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>