drm/gma500/cdv: Make use of the generic clock code

Add chip specific callbacks for the generic and non-generic clock
calculation code. Also remove as much dupilicated code as possible.

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
diff --git a/drivers/gpu/drm/gma500/cdv_device.h b/drivers/gpu/drm/gma500/cdv_device.h
index 9561e17..0fcb608 100644
--- a/drivers/gpu/drm/gma500/cdv_device.h
+++ b/drivers/gpu/drm/gma500/cdv_device.h
@@ -17,6 +17,7 @@
 
 extern const struct drm_crtc_helper_funcs cdv_intel_helper_funcs;
 extern const struct drm_crtc_funcs cdv_intel_crtc_funcs;
+extern const struct gma_clock_funcs cdv_clock_funcs;
 extern void cdv_intel_crt_init(struct drm_device *dev,
 			struct psb_intel_mode_device *mode_dev);
 extern void cdv_intel_lvds_init(struct drm_device *dev,