clk: mediatek: mt2712: Migrate topckgen/mcucfg to mtk_clk_simple_probe()

clk: mediatek: mt2712: Migrate topckgen/mcucfg to mtk_clk_simple_probe()

Now that the common mtk_clk_simple_{probe,remove}() functions can deal
with divider clocks it is possible to migrate more clock drivers to it:
in this case, it's about topckgen.
While at it, also perform a fast migration for mcucfg.

Thanks to the conversion, more error handling was added to the clocks
registration.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20230306140543.1813621-6-angelogioacchino.delregno@collabora.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>