driconf: remove the adaptive sync special case for mpv

driconf: remove the adaptive sync special case for mpv

mpv didn't ask to be on this list, was never consulted about being
on this list and to the best of my knowledge has no problem with
adaptive sync. If there is an issue exposed by mpv having adaptive
sync enabled, then it should be reported to mpv, so that it can be
fixed in mpv.

The only problem I could remotely imagine with mpv and VRR is that
its display-resample mode tries to do something similar, and the
two mechanisms will likely race each other to the bottom, but the
display-resample mode is not the default and this is already a
known issue on Windows so users wouldn't expect this to behave any
differently on Linux.

In short, please don't try to make a list of all applications that
are not video games, it is not conducive to having a good time on
the computer.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20701>