arm64: dts: meson: Describe G12b GPU as coherent

stable inclusion
from stable-5.10.14
commit beba2ac6b1205e614b7a39c3f9b0718c38fa57e7
bugzilla: 48051

--------------------------------

commit 03544505 upstream.

According to a downstream commit I found in the Khadas vendor kernel,
the GPU on G12b is wired up for ACE-lite, so (now that Panfrost knows
how to handle this properly) we should describe it as such. Otherwise
the mismatch leads to all manner of fun with mismatched attributes and
inadvertently snooping stale data from caches, which would account for
at least some of the brokenness observed on this platform.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/765446e529e50b304af63432da7836c4d31eb8d4.1600780574.git.robin.murphy@arm.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>