mailbox: zynqmp: Fix counts of child nodes

stable inclusion
from stable-v5.10.180
commit 26b1b0d0bebdb45ba1e33590313a4e345e1e18d8
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=26b1b0d0bebdb45ba1e33590313a4e345e1e18d8



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[ Upstream commit f72f805e ]

If child mailbox node status is disabled it causes
crash in interrupt handler. Fix this by assigning
only available child node during driver probe.

Fixes: 4981b82b ("mailbox: ZynqMP IPI mailbox controller")
Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230311012407.1292118-2-tanmay.shah@amd.com


Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>