dpaa2-switch: do not accept VLAN uppers while bridged

dpaa2-switch: do not accept VLAN uppers while bridged

The dpaa2-switch driver does not support VLAN uppers while its ports are
bridged. This scenario tried to be prevented by rejecting a bridge join
while VLAN uppers exist but the reverse order was still possible.

This patches adds a check so that the dpaa2-switch also does not accept
VLAN uppers while bridged.

Fixes: f48298d3fbfa ("staging: dpaa2-switch: move the driver out of staging")
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://patch.msgid.link/20260618092813.432535-2-ioana.ciornei@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>