net/qed: allow old cards not supporting "num_images" to work

net/qed: allow old cards not supporting "num_images" to work

Commit 43645ce03e00 ("qed: Populate nvm image attribute shadow.")
added support for populating flash image attributes, notably
"num_images". However, some cards were not able to return this
information. In such cases, the driver would return EINVAL, causing the
driver to exit.

Add check to return EOPNOTSUPP instead of EINVAL when the card is not
able to return these information. The caller function already handles
EOPNOTSUPP without error.

Fixes: 43645ce03e00 ("qed: Populate nvm image attribute shadow.")
Co-developed-by: Florian Forestier <florian@forestier.re>
Signed-off-by: Florian Forestier <florian@forestier.re>
Signed-off-by: Louis Leseur <louis.leseur@gmail.com>
Link: https://patch.msgid.link/20241128083633.26431-1-louis.leseur@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>