drm/panfrost: add amlogic reset quirk callback

The T820, G31 & G52 GPUs integrated by Amlogic in the respective GXM,
G12A/SM1 & G12B SoCs needs a quirk in the PWR registers at the GPU reset
time.

Since the Amlogic's integration of the GPU cores with the SoC is not
publicly documented we do not know what does these values, but they
permit having a fully functional GPU running with Panfrost.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
[Steven: Fix typo in commit log]
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200916150147.25753-3-narmstrong@baylibre.com