net: dsa: tag_qca: fix wrong MGMT_DATA2 size

net: dsa: tag_qca: fix wrong MGMT_DATA2 size

commit 401566e4f5e60229c6b369b900f283d42ae78ef9 upstream.

It was discovered that MGMT_DATA2 can contain up to 28 bytes of data
instead of the 12 bytes written in the Documentation by accounting the
limit of 16 bytes declared in Documentation subtracting the first 4 byte
in the packet header.

Update the define with the real world value.

Tested-by: Ronald Wahl <ronald.wahl@raritan.com>
Fixes: 032a9e7ab521 ("net: dsa: tag_qca: add define for handling mgmt Ethernet packet")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Cc: stable@vger.kernel.org # v5.18+
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>