drm/vc4: Add the 2711 HVS as a suitable DMA node

With vc4-drv node not being under /soc on Pi4, we need to
adopt the correct DMA parameters from a suitable sub-component.
Add "brcm,bcm2711-hvs" to that list of components.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>