gpu: ipu-v3: Use ERR_CAST instead of ERR_PTR(PTR_ERR())

Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...)).

Generated by: scripts/coccinelle/api/err_cast.cocci

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>