dmaengine: sun6i: Add support for H6 DMA

H6 DMA has more than 32 supported DRQs, which means that configuration
register is slightly rearranged. It also needs additional clock to be
enabled.

Add support for it.

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>