drm/msm/dsi: Correct io_start for MSM8994 (20nm PHY)

stable inclusion
from stable-5.10.20
commit 92a1514e0a5d426b6002e2302985193260985d52
bugzilla: 50608

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

[ Upstream commit 33a7808c ]

The previous registers were *almost* correct, but instead of
PHYs, they were pointing at DSI PLLs, resulting in the PHY id
autodetection failing miserably.

Fixes: dcefc117 ("drm/msm/dsi: Add support for msm8x94")
Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>