drm: remove unused code

remove declared but unused functions from drmP.h, fix the comments
where necessary. Also, remove drm_mem_info which is unused.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 44a5d0a..c869436 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -305,7 +305,7 @@
  * \param dev DRM device.
  *
  * Initializes the IRQ related data. Installs the handler, calling the driver
- * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
+ * \c irq_preinstall() and \c irq_postinstall() functions
  * before and after the installation.
  */
 int drm_irq_install(struct drm_device *dev)
@@ -385,7 +385,7 @@
  *
  * \param dev DRM device.
  *
- * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
+ * Calls the driver's \c irq_uninstall() function, and stops the irq.
  */
 int drm_irq_uninstall(struct drm_device *dev)
 {