drm/omap: Fix kernel docs

Fix doc related warnings seen with W=1: the function names have changed
but the docs have not been changed accordingly.

Signed-off-by: Tomi Valkeinen <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]
Reviewed-by: Laurent Pinchart <[e-mail]>

drivers/gpu/drm/omapdrm/omap_gem.c

···
 }
 
 /**
- * omap_gem_dumb_map	-	buffer mapping for dumb interface
+ * omap_gem_dumb_map_offset - create an offset for a dumb buffer
  * @file: our drm client file
  * @dev: drm device
  * @handle: GEM handle to the object (from dumb_create)

drivers/gpu/drm/omapdrm/omap_irq.c

···
 }
 
 /**
- * enable_vblank - enable vblank interrupt events
+ * omap_irq_enable_vblank - enable vblank interrupt events
  * @crtc: DRM CRTC
  *
  * Enable vblank interrupts for @crtc.  If the device doesn't have
···
 }
 
 /**
- * disable_vblank - disable vblank interrupt events
+ * omap_irq_disable_vblank - disable vblank interrupt events
  * @crtc: DRM CRTC
  *
  * Disable vblank interrupts for @crtc.  If the device doesn't have