phy: qcom-qmp-usb: drop power-down delay config

phy: qcom-qmp-usb: drop power-down delay config

[ Upstream commit 38cd167d1fc6b5bf038229b1fa02bb1f551a564f ]

The power-down delay was included in the first version of the QMP driver
as an optional delay after powering on the PHY (using
POWER_DOWN_CONTROL) and just before starting it. Later changes modified
this sequence by powering on before initialising the PHY, but the
optional delay stayed where it was (i.e. before starting the PHY).

The vendor driver does not use a delay before starting the PHY and this
is likely not needed on any platform unless there is a corresponding
delay in the vendor kernel init sequence tables (i.e. in devicetree).

Let's keep the delay for now, but drop the redundant delay period
configuration while increasing the unnecessarily low timer slack
somewhat.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20221012081241.18273-15-johan+linaro@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Stable-dep-of: 922adfd59efd ("phy: qcom-qmp-usb: correct registers layout for IPQ8074 USB3 PHY")
Signed-off-by: Sasha Levin <sashal@kernel.org>