clk: mediatek: clk-mt7986-topckgen: Migrate to mtk_clk_simple_probe()

clk: mediatek: clk-mt7986-topckgen: Migrate to mtk_clk_simple_probe()

There are no more non-common calls in clk_mt7986_topckgen_probe():
migrate this driver to mtk_clk_simple_probe().

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20230120092053.182923-24-angelogioacchino.delregno@collabora.com
Tested-by: Mingming Su <mingming.su@mediatek.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>