drm/amd/display: fix HDCP reset sequence on reinitialize

stable inclusion
from stable-5.10.51
commit fb7479d64d77a3bb0ee992f9e450cf52d56c6b2c
bugzilla: 175263 https://gitee.com/openeuler/kernel/issues/I4DT6F

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fb7479d64d77a3bb0ee992f9e450cf52d56c6b2c



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[ Upstream commit 99c248c4 ]

[why]
When setup is called after hdcp has already setup,
it would cause to disable HDCP flow won’t execute.

[how]
Don't clean up hdcp content to be 0.

Signed-off-by: Brandon Syu <Brandon.Syu@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Wayne Lin <waynelin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.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>