spi: rockchip: Call the dedicated transfer completion function.

spi_finalize_current_transfer currently only calls "complete", so no
functional change is expected.

Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Link: https://lore.kernel.org/r/f3e1cf19a7dcdd77adc0a719adf46449b84ccadd.1610062884.git.plr.vincent@gmail.com


Signed-off-by: Mark Brown <broonie@kernel.org>