video: ipu: fix debug and comment

- fix debug pixel clk display and add unit
- fix some comments

Cc: Stefano Babic <sbabic@denx.de>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
diff --git a/drivers/video/ipu_disp.c b/drivers/video/ipu_disp.c
index 948e1fc..e97a204 100644
--- a/drivers/video/ipu_disp.c
+++ b/drivers/video/ipu_disp.c
@@ -887,7 +887,7 @@
 	v_total = height + v_sync_width + v_start_width + v_end_width;
 
 	/* Init clocking */
-	debug("pixel clk = %d\n", pixel_clk);
+	debug("pixel clk = %dHz\n", pixel_clk);
 
 	if (sig.ext_clk) {
 		if (!(g_di1_tvout && (disp == 1))) { /*not round div for tvout*/