drm/omapdrm: Remove outdated comment

The comment refers to drm_irq_install() et al, which are not used by
omapdrm. The functions are part of the DRM IRQ midlayer and shouldn't
be used any longer. Remove the comment.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210706073125.7689-1-tzimmermann@suse.de

drivers/gpu/drm/omapdrm/omap_irq.c

@@ -253,13 +253,6 @@ static const u32 omap_underflow_irqs[] = {
 	[OMAP_DSS_VIDEO3] = DISPC_IRQ_VID3_FIFO_UNDERFLOW,
 };
 
-/*
- * We need a special version, instead of just using drm_irq_install(),
- * because we need to register the irq via omapdss.  Once omapdss and
- * omapdrm are merged together we can assign the dispc hwmod data to
- * ourselves and drop these and just use drm_irq_{install,uninstall}()
- */
-
 int omap_drm_irq_install(struct drm_device *dev)
 {
 	struct omap_drm_private *priv = dev->dev_private;