phy: qcom-qmp-combo: fix NULL-deref on runtime resume

In the Linux kernel, the following vulnerability has been resolved: phy: qcom-qmp-combo: fix NULL-deref on runtime resume Commit fc64623637da ("phy: qcom-qmp-combo,usb: add support for separate PCS_USB region") started treating the PCS_USB registers as potentially separate from the PCS registers but used the wrong base when no PCS_USB offset has been provided. Fix the PCS_USB base used at runtime resume to prevent dereferencing a NULL pointer on platforms that do not provide a PCS_USB offset (e.g. SC7180).