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

commit 04948e7 upstream.

Commit fc64623 ("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).

Fixes: fc64623 ("phy: qcom-qmp-combo,usb: add support for separate PCS_USB region")
Cc: [email protected]	# 5.20
Signed-off-by: Johan Hovold <[email protected]>
Reviewed-by: Dmitry Baryshkov <[email protected]>
Reviewed-by: Andrew Halaney <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

drivers/phy/qualcomm/phy-qcom-qmp-combo.c

@@ -1914,7 +1914,7 @@ static void qcom_qmp_phy_combo_enable_autonomous_mode(struct qmp_phy *qphy)
 static void qcom_qmp_phy_combo_disable_autonomous_mode(struct qmp_phy *qphy)
 {
 	const struct qmp_phy_cfg *cfg = qphy->cfg;
-	void __iomem *pcs_usb = qphy->pcs_usb ?: qphy->pcs_usb;
+	void __iomem *pcs_usb = qphy->pcs_usb ?: qphy->pcs;
 	void __iomem *pcs_misc = qphy->pcs_misc;
 
 	/* Disable i/o clamp_n on resume for normal mode */