soc: mediatek: SVS: Fix MT8192 GPU node name

Device tree node names should be generic. The planned device node name
for the GPU, according to the bindings and posted DT changes, is "gpu",
not "mali".

Fix the GPU node name in the SVS driver to follow.

Fixes: 0bbb09b2 ("soc: mediatek: SVS: add mt8192 SVS GPU driver")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Link: https://lore.kernel.org/r/20230531063532.2240038-1-wenst@chromium.org


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>