niri-config: add keep-max-bpc-unchanged option (#2195)

* niri-config: add disable-set-bpc option
setting bpc to 8 bricks some OLED displays driven by amdgpu

* change to keep-max-bpc-unchanged and add to wiki

* fmt

* Update wiki/Configuration:-Debug-Options.md

---------

Co-authored-by: Ivan Molodetskikh <yalterz@gmail.com>

niri-config/src/lib.rs

@@ -2339,6 +2339,8 @@ pub struct DebugConfig {
     #[knuffel(child)]
     pub disable_direct_scanout: bool,
     #[knuffel(child)]
+    pub keep_max_bpc_unchanged: bool,
+    #[knuffel(child)]
     pub restrict_primary_scanout_to_matching_format: bool,
     #[knuffel(child, unwrap(argument))]
     pub render_drm_device: Option<PathBuf>,
@@ -5434,6 +5436,7 @@ mod tests {
                 enable_overlay_planes: false,
                 disable_cursor_plane: false,
                 disable_direct_scanout: false,
+                keep_max_bpc_unchanged: false,
                 restrict_primary_scanout_to_matching_format: false,
                 render_drm_device: Some(
                     "/dev/dri/renderD129",