clk: mediatek: Add MT8195 topckgen clock support

Add MT8195 topckgen clock controller which provides muxes, dividers
to handle variety clock selection in other IP blocks.

Signed-off-by: Chun-Jie Chen <chun-jie.chen@mediatek.com>
Link: https://lore.kernel.org/r/20210914021633.26377-8-chun-jie.chen@mediatek.com


Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>