media: venus: Fix firmware path for resources

The firmware path for some of the resources is still the old format. This
fixes the path to address the firmware correctly using the new .mbn
format.

Signed-off-by: Patrick Whewell <patrick.whewell@sightlineapplications.com>
Signed-off-by: Stanimir Varbanov <stanimir.k.varbanov@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>