drm/bridge: dw-hdmi: Sync comment block with actual bus formats order

Commit d3d6b1bf ("drm: bridge: dw_hdmi: fix preference of RGB modes
over YUV420") changed the order of the output bus formats, but missed to
update accordingly the "Possible output formats" comment section above
dw_hdmi_bridge_atomic_get_output_bus_fmts().

Fix the misleading comment block and a context related typo.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250204-dw-hdmi-bus-fmt-order-v2-1-d0aaeb7a697a@collabora.com