net: devmem: allow bind-rx from non-init user namespaces

net: devmem: allow bind-rx from non-init user namespaces

NETDEV_CMD_BIND_RX is currently GENL_ADMIN_PERM, which checks
CAP_NET_ADMIN against init userns. With recent container/netkit/ns
support for devmem, other userns/netns use cases come online and require
bind-rx to allow CAP_NET_ADMIN in non-init user ns as well.

Switch the flag to GENL_UNS_ADMIN_PERM to allow bind-rx for
CAP_NET_ADMIN in the netns's owning userns as well.

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260602-nl-prov-v2-1-ad721142c641@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>