color: relax set_max_cll, set_max_fall

Originally, st2084_pq was the only transfer function providing cd/m². Since MaxCLL and MaxFALL are defined in cd/m², it made sense to restrict them to st2084_pq.

Nowadays we have set_luminances and its defaults, meaning we can always compute cd/m², even from proportional luminance. We can allow MaxCLL and MaxFALL always.

MaxCLL and MaxFALL were originally intended for the tone mapping in st2084_pq mode displays as the video system inherently requires. These values are unique from all the other values in the parametric interface, and presumably they should help automatic tone mapping also outside of st2084_pq.

suggested by @Zamundaaa in mesa/mesa!31991 (comment 2647062)

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This MR also removes inconsistent_set error code.