phy: qcom: qmp-usb-legacy: fix NULL-deref on runtime suspend

In the Linux kernel, the following vulnerability has been resolved:

phy: qcom: qmp-usb-legacy: fix NULL-deref on runtime suspend

Commit 413db06c05e7 ("phy: qcom-qmp-usb: clean up probe initialisation")

removed most users of the platform device driver data from the

qcom-qmp-usb driver, but mistakenly also removed the initialisation

despite the data still being used in the runtime PM callbacks. This bug

was later reproduced when the driver was copied to create the

qmp-usb-legacy driver.

Restore the driver data initialisation at probe to avoid a NULL-pointer

dereference on runtime suspend.

Apparently no one uses runtime PM, which currently needs to be enabled

manually through sysfs, with these drivers.