net: dsa: mv88e6xxx: add mv88e6321 rsvd2cpu

stable inclusion
from stable-v5.10.180
commit f47f0fb5b58b92e0e256fd8e90211fe42093aaad
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8FC2O

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f47f0fb5b58b92e0e256fd8e90211fe42093aaad



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[ Upstream commit 66863178 ]

Add rsvd2cpu capability for mv88e6321 model, to allow proper bpdu
processing.

Signed-off-by: Angelo Dureghello <angelo.dureghello@timesys.com>
Fixes: 51c901a7 ("net: dsa: mv88e6xxx: distinguish Global 2 Rsvd2CPU")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>