drm/panfrost: Add new compatible for Mali on the MT8183 SoC

drm/panfrost: Add new compatible for Mali on the MT8183 SoC

The "mediatek,mt8183-mali" compatible uses platform data that calls for
getting (and managing) two regulators ("mali" and "sram") but devfreq
does not support this usecase, resulting in DVFS not working.

Since a lot of MediaTek SoCs need to set the voltages for the GPU SRAM
regulator in a specific relation to the GPU VCORE regulator, a MediaTek
SoC specific driver was introduced to automatically satisfy, through
coupling, these constraints: this means that there is at all no need to
manage both regulators in panfrost but to otherwise just manage the main
"mali" (-> gpu vcore) regulator instead.

Keeping in mind that we cannot break the ABI, the most sensible route
(avoiding hacks and uselessly overcomplicated code) to get a MT8183
node with one power supply was to add a new "mediatek,mt8183b-mali"
compatible, which effectively deprecates the former.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230316102041.210269-12-angelogioacchino.delregno@collabora.com