dmaengine: sun6i: Add a quirk for additional mbus clock

H6 DMA controller needs additional mbus clock to be enabled.

Add a quirk for it and handle it accordingly.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>