usb: phy: msm: switch over to writel()

Remove that single instance of writel_relaxed()
call which is only available on ARM architecture.

This will let us build test this driver on all
different architectures.

Reviewed-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/phy/phy-msm-usb.c b/drivers/usb/phy/phy-msm-usb.c
index 591b406..c522c4f 100644
--- a/drivers/usb/phy/phy-msm-usb.c
+++ b/drivers/usb/phy/phy-msm-usb.c
@@ -1600,7 +1600,7 @@
 		if (IS_ERR(phy_select))
 			return PTR_ERR(phy_select);
 		/* Enable second PHY with the OTG port */
-		writel_relaxed(0x1, phy_select);
+		writel(0x1, phy_select);
 	}
 
 	dev_info(&pdev->dev, "OTG regs = %p\n", motg->regs);