macsec: limit ICV length to 16 octets

macsec: limit ICV length to 16 octets

IEEE 802.1AE-2006 standard recommends that the ICV element in a MACsec
frame should not exceed 16 octets: add MACSEC_STD_ICV_LEN in uapi
definitions accordingly, and avoid accepting configurations where the ICV
length exceeds the standard value. Leave definition of MACSEC_MAX_ICV_LEN
unchanged for backwards compatibility with userspace programs.

Fixes: dece8d2b78d1 ("uapi: add MACsec bits")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 2ccbe2cb79f2f74ab739252299b6f9ff27586f2c)

Orabug: 24614549

Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>