clk: baikal-t1: Add shared xGMAC ref/ptp clocks internal parent

stable inclusion
from stable-v5.10.150
commit 5f143f3bc2e0a501e945e4bcda882f2eff90eaac
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5f143f3bc2e0a501e945e4bcda882f2eff90eaac



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[ Upstream commit e2eef312 ]

Baikal-T1 CCU reference manual says that both xGMAC reference and xGMAC
PTP clocks are generated by two different wrappers with the same constant
divider thus each producing a 156.25 MHz signal. But for some reason both
of these clock sources are gated by a single switch-flag in the CCU
registers space - CCU_SYS_XGMAC_BASE.BIT(0). In order to make the clocks
handled independently we need to define a shared parental gate so the base
clock signal would be switched off only if both of the child-clocks are
disabled.

Note the ID is intentionally set to -2 since we are going to add a one
more internal clock identifier in the next commit.

Fixes: 353afa3a ("clk: Add Baikal-T1 CCU Dividers driver")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20220929225402.9696-4-Sergey.Semin@baikalelectronics.ru


Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>