drm: sti: sti_hqvdp: undo preparation of a clock source.

Undo preparation of a clock source, if sti_hqvdp_start_xp70 and
sti_hqvdp_atomic_check are not successful.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/7afad3012fb6e40f43a1eb5a64dc6364c38bd052.1498039961.git.arvind.yadav.cs@gmail.com

drivers/gpu/drm/sti/sti_hqvdp.c

@@ -958,6 +958,7 @@ static void sti_hqvdp_start_xp70(struct sti_hqvdp *hqvdp)
 	}
 	if (i == POLL_MAX_ATTEMPT) {
 		DRM_ERROR("Could not reset\n");
+		clk_disable_unprepare(hqvdp->clk);
 		goto out;
 	}
 
@@ -994,6 +995,7 @@ static void sti_hqvdp_start_xp70(struct sti_hqvdp *hqvdp)
 	}
 	if (i == POLL_MAX_ATTEMPT) {
 		DRM_ERROR("Could not boot\n");
+		clk_disable_unprepare(hqvdp->clk);
 		goto out;
 	}
 
@@ -1081,6 +1083,7 @@ static int sti_hqvdp_atomic_check(struct drm_plane *drm_plane,
 					    &hqvdp->vtg_nb,
 					    crtc)) {
 			DRM_ERROR("Cannot register VTG notifier\n");
+			clk_disable_unprepare(hqvdp->clk_pix_main);
 			return -EINVAL;
 		}
 		hqvdp->vtg_registered = true;