net: dsa: mv88e6xxx: enable SerDes PCS register dump via ethtool -d on Topaz

stable inclusion
from stable-5.10.54
commit f7ee361182e05a39a96528b581ae9215a9d26161
bugzilla: 175586 https://gitee.com/openeuler/kernel/issues/I4DVDU

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=f7ee361182e05a39a96528b581ae9215a9d26161



--------------------------------

commit 953b0dcb upstream.

Commit bf3504ce ("net: dsa: mv88e6xxx: Add 6390 family PCS
registers to ethtool -d") added support for dumping SerDes PCS registers
via ethtool -d for Peridot.

The same implementation is also valid for Topaz, but was not
enabled at the time.

Signed-off-by: Marek Behún <kabel@kernel.org>
Fixes: bf3504ce ("net: dsa: mv88e6xxx: Add 6390 family PCS registers to ethtool -d")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>