drm/arcpgu: use dedicated memory area for frame buffer
Now when ARC supports reserved memory areas and
per-device coherent DMA allocations we may switch ARC PGU
to use of those dedicated areas.
One of the benefits we may move frame-buffer area out
from IO Coherency aperture and so significantly
reduce IOC utilization allowing less demanding
peripherals to use all perks of IOC.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-kernel@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org