[media] st-hva: fix some error handling in hva_hw_probe()

[media] st-hva: fix some error handling in hva_hw_probe()

The devm_ioremap_resource() returns error pointers, never NULL.  The
platform_get_resource() returns NULL on error, never error pointers.
The error code needs to be set, as well.  The current code returns
PTR_ERR(NULL) which is success.

Fixes: 25c7252c3150 ("[media] st-hva: multi-format video encoder V4L2 driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jean-Christophe Trotin <jean-christophe.trotin@st.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>