soc: mediatek: cmdq: add clear option in cmdq_pkt_wfe api

Add clear parameter to let client decide if
event should be clear to 0 after GCE receive it.

Signed-off-by: Dennis YC Hsieh <dennis-yc.hsieh@mediatek.com>
Acked-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Link: https://lore.kernel.org/r/1594136714-11650-9-git-send-email-dennis-yc.hsieh@mediatek.com


[mb: fix commit message]
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>