drm/rockchip: Change the scl_vop_cal_scl_fac to pass drm_format_info

The Rockchip VOP driver has a function, scl_vop_cal_scl_fac, that will
lookup the drm_format_info structure from the fourcc passed to it by its
caller.

However, its only caller already derefences the drm_format_info structure
it has access to to retrieve that fourcc. Change the prototype of that
function to pass the drm_format_info structure directly, removing the need
for an extra lookup.

Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Suggested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/27b0041c7977402df4a087c78d2849ffe51c9f1c.1558002671.git-series.maxime.ripard@bootlin.com