drm: Constify the pretty-print functions

The structures and strings involved with various pretty-print functions
aren't meant to be modified, so make them all const. The exception is
drm_connector_enum_list which does get modified in drm_connector_init().

While at it move the drm_get_connector_status_name() prototype from
drmP.h to drm_crtc.h where it belongs.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 2cbbfd4..53c33e2 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -897,12 +897,13 @@
 
 extern void drm_encoder_cleanup(struct drm_encoder *encoder);
 
-extern char *drm_get_connector_name(struct drm_connector *connector);
-extern char *drm_get_dpms_name(int val);
-extern char *drm_get_dvi_i_subconnector_name(int val);
-extern char *drm_get_dvi_i_select_name(int val);
-extern char *drm_get_tv_subconnector_name(int val);
-extern char *drm_get_tv_select_name(int val);
+extern const char *drm_get_connector_name(const struct drm_connector *connector);
+extern const char *drm_get_connector_status_name(enum drm_connector_status status);
+extern const char *drm_get_dpms_name(int val);
+extern const char *drm_get_dvi_i_subconnector_name(int val);
+extern const char *drm_get_dvi_i_select_name(int val);
+extern const char *drm_get_tv_subconnector_name(int val);
+extern const char *drm_get_tv_select_name(int val);
 extern void drm_fb_release(struct drm_file *file_priv);
 extern int drm_mode_group_init_legacy_group(struct drm_device *dev, struct drm_mode_group *group);
 extern bool drm_probe_ddc(struct i2c_adapter *adapter);
@@ -994,7 +995,7 @@
 extern int drm_mode_create_scaling_mode_property(struct drm_device *dev);
 extern int drm_mode_create_dithering_property(struct drm_device *dev);
 extern int drm_mode_create_dirty_info_property(struct drm_device *dev);
-extern char *drm_get_encoder_name(struct drm_encoder *encoder);
+extern const char *drm_get_encoder_name(const struct drm_encoder *encoder);
 
 extern int drm_mode_connector_attach_encoder(struct drm_connector *connector,
 					     struct drm_encoder *encoder);
@@ -1094,6 +1095,6 @@
 extern int drm_format_plane_cpp(uint32_t format, int plane);
 extern int drm_format_horz_chroma_subsampling(uint32_t format);
 extern int drm_format_vert_chroma_subsampling(uint32_t format);
-extern char *drm_get_format_name(uint32_t format);
+extern const char *drm_get_format_name(uint32_t format);
 
 #endif /* __DRM_CRTC_H__ */