phy: qcom-qmp-pcie: fix initialisation reset

Add the missing delay after asserting reset. This is specifically needed
for the reset to have any effect on SC8280XP.

The vendor driver uses a 1 ms delay, but that seems a bit excessive.
Instead use a 200 us delay which appears to be more than enough and also
matches the UFS reset delay added by commit 870b1279 ("scsi:
ufs-qcom: Add reset control support for host controller").

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>