drm: of: drm_of_find_panel_or_bridge: move misplaced comment

This comment is misleading as it refers to one of the inner if() branches
only, not the whole outer if(). Move it to the branch it refers to.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250214-drm-assorted-cleanups-v7-2-88ca5827d7af@bootlin.com