drm/kms_helper: Add a common place to call init and exit functions.

The module_init and module_exit functions will start here, and call the
subsequent init's and exit's.

v10:
 - Keep __init on drm_fb_helper init function.
 - Move MODULE_* macros to the common file.

Signed-off-by: Rafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1453417821-2811-2-git-send-email-rafael.antognolli@intel.com
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index d8a40df..062723b 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -219,6 +219,7 @@
 };
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
+int drm_fb_helper_modinit(void);
 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 			   const struct drm_fb_helper_funcs *funcs);
 int drm_fb_helper_init(struct drm_device *dev,
@@ -283,6 +284,11 @@
 int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
 				       struct drm_connector *connector);
 #else
+static inline int drm_fb_helper_modinit(void)
+{
+	return 0;
+}
+
 static inline void drm_fb_helper_prepare(struct drm_device *dev,
 					struct drm_fb_helper *helper,
 					const struct drm_fb_helper_funcs *funcs)