clk: mediatek: clk-mt8192-mfg: Propagate rate changes to parent

Following what was done on MT8183 and MT8195, also propagate the rate
changes to MFG_BG3D's parent on MT8192 to allow for proper GPU DVFS.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20220927101128.44758-10-angelogioacchino.delregno@collabora.com


Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>