[PATCH v3 12/15] clk: mediatek: Add MT8186 vencsys clock support

[Miles Chen]

> Add MT8186 vencsys clock controller which provide clock gate
> control for video encoder.
> 
> Signed-off-by: Chun-Jie Chen <chun-jie.chen at mediatek.com>
> Acked-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>

Reviewed-by: Miles Chen <miles.chen at mediatek.com>