options: remove the player argument from --media-controls

It is now handled internally by the libmpv profile.

Since `player` was the default option, the impact should be minimal, as it
is uncommon to override the default option with the same value.
yes/no args will function the same way as before this commit.

DOCS/interface-changes/media-controls-player.txt

@@ -0,0 +1 @@
+remove `player` argument form `--media-controls`, it's handled internally now.