usb: phy: msm: Make phy_reset clk and reset line optional.

This patch makes the phy reset clk and reset line optional as this clk
is not available on boards like IFC6410 with APQ8064.

phy-reset clk is only used as argument to the mach level callbacks, so
this patch adds condition before clk_get calls so that the driver
wouldn't fail on SOCs which do not have this support.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/phy/phy-msm-usb.c

@@ -281,7 +281,7 @@ static int msm_otg_phy_clk_reset(struct msm_otg *motg)
 {
 	int ret = 0;
 
-	if (motg->pdata->phy_clk_reset && motg->phy_reset_clk)
+	if (motg->pdata->phy_clk_reset)
 		ret = motg->pdata->phy_clk_reset(motg->phy_reset_clk);
 	else if (motg->phy_rst)
 		ret = reset_control_reset(motg->phy_rst);
@@ -1554,11 +1554,14 @@ static int msm_otg_probe(struct platform_device *pdev)
 	phy = &motg->phy;
 	phy->dev = &pdev->dev;
 
+	if (motg->pdata->phy_clk_reset) {
 		motg->phy_reset_clk = devm_clk_get(&pdev->dev,
 					   np ? "phy" : "usb_phy_clk");
+
 		if (IS_ERR(motg->phy_reset_clk)) {
 			dev_err(&pdev->dev, "failed to get usb_phy_clk\n");
-		motg->phy_reset_clk = NULL;
+			return PTR_ERR(motg->phy_reset_clk);
+		}
 	}
 
 	motg->clk = devm_clk_get(&pdev->dev, np ? "core" : "usb_hs_clk");