libs: encoder: h265: modify set_max_profile to set_allowed_profiles.
In h265, bigger profile idc may not be compatible with the small profile
idc. And more important, there are multi profiles with the same profile
idc. Such as main-422-10, main-444 and main-444-10, they all have profile
idc 4.
So recording the max profile idc is not enough, the encoder needs to know
all allowed profiles when deciding the real profile.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-vaapi/-/merge_requests/349>