arm64: dts: mediatek: mt8192: Fix GPU thermal zone name for SVS

This SoC has two GPU related thermal zones: the primary zone must be
called "gpu-thermal" for SVS to pick it up.

Fixes: c7a72805 ("arm64: dts: mediatek: mt8192: Add thermal nodes and thermal zones")
Link: https://lore.kernel.org/r/20240410083002.1357857-3-angelogioacchino.delregno@collabora.com


Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>