This constant was always defined to 0, and recently got removed in
upstream commit a07ea4d9941af5a0c6f0be2a71b51ac9c083c5e5 ("genetlink: no
longer support using static family IDs")
Fixes libnl-tiny builds with latest upstream kernels.
Fixes: d723f2573a ("libnl-tiny: remove include/linux overrides to fix various build issues")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>