clk: mediatek: clk-mux: Add ops for mux gates with set/clr/upd and FENC

clk: mediatek: clk-mux: Add ops for mux gates with set/clr/upd and FENC

MT8196 uses set/clr/upd registers for mux gate enable/disable control,
along with a FENC bit to check the status. Add new set of mux gate
clock operations with support for set/clr/upd and FENC status logic.

Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>