MLK-20208-4 mxc IPUv3: disp: Avoid division by zero in ipu_init_sync_panel()

MLK-20208-4 mxc IPUv3: disp: Avoid division by zero in ipu_init_sync_panel()

To avoid potential division by zero in ipu_init_sync_panel(),
let's check the rounded_pixel_clk rate prior to that.

Detected by CoverityScan, CID#56278 ("Division or modulo by zero")

Signed-off-by: Liu Ying <victor.liu@nxp.com>
(cherry picked from commit 1523150b71f1aa0610f61ea47a9f3bdbcda92522)
Signed-off-by: Arulpandiyan Vadivel <arulpandiyan_vadivel@mentor.com>
Signed-off-by: Shrikant Bobade <Shrikant_Bobade@mentor.com>
(cherry picked from commit 5e2882f2fa1e852e6c405e38109505eae1459c90)