phy: qcom-qusb2: Add missing vdd supply

Per downstream kernel, beside vdda-pll and vdda-phy-dpdm, vdd is also a
required supply for QUSB2 PHY digital circuit operation.  The driver
works right now likely because firmware already sets it up.  Add it for
correctness and completeness.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Link: https://lore.kernel.org/r/20210928022002.26286-3-shawn.guo@linaro.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/qualcomm/phy-qcom-qusb2.c

@@ -371,7 +371,7 @@ static const struct qusb2_phy_cfg sm6115_phy_cfg = {
 };
 
 static const char * const qusb2_phy_vreg_names[] = {
-	"vdda-pll", "vdda-phy-dpdm",
+	"vdd", "vdda-pll", "vdda-phy-dpdm",
 };
 
 #define QUSB2_NUM_VREGS		ARRAY_SIZE(qusb2_phy_vreg_names)