drm/fb-helper: Fix sparse warnings

drm/drm_fb_helper.c:2306:12: warning: symbol 'drm_fb_helper_modinit' was not declared. Should it be static?

While at it, move the lefover static inline to the right place.

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474292035-15695-4-git-send-email-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h b/drivers/gpu/drm/drm_crtc_helper_internal.h
index 4e6b57a..28295e5 100644
--- a/drivers/gpu/drm/drm_crtc_helper_internal.h
+++ b/drivers/gpu/drm/drm_crtc_helper_internal.h
@@ -29,7 +29,14 @@
 #include <drm/drm_dp_helper.h>
 
 /* drm_fb_helper.c */
+#ifdef CONFIG_DRM_FBDEV_EMULATION
 int drm_fb_helper_modinit(void);
+#else
+static inline int drm_fb_helper_modinit(void)
+{
+	return 0;
+}
+#endif
 
 /* drm_dp_aux_dev.c */
 #ifdef CONFIG_DRM_DP_AUX_CHARDEV