drm/vc4: dsi: Add correct stop condition to vc4_dsi_encoder_disable iteration

stable inclusion
from stable-v5.10.137
commit cefc8e7e0ea4e11f750c4abbb6f5ebc8f85110d5
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cefc8e7e0ea4e11f750c4abbb6f5ebc8f85110d5



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[ Upstream commit 7bcb9c8d ]

vc4_dsi_encoder_disable is partially an open coded version of
drm_bridge_chain_disable, but it missed a termination condition
in the loop for ->disable which meant that no post_disable
calls were made.

Add in the termination clause.

Fixes: 033bfe75 ("drm/vc4: dsi: Fix bridge chain handling")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-17-maxime@cerno.tech


Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>