fsl/usb: Limit phy_type comparison to first four characters

Use first four characters for phy_type comparison. Strcmp() should not
be used to check the phy_type string which maybe parsed by hwconfig_subarg().
Hwconfig_subarg() returns part of hwconfig string starting from
phy_type value till the end of the string. Since phy_type could be
either "utmi" or "ulpi", strncmp() should be used so that a comparison
of "utmi;fsl_ddr:bank_intlv=auto" with "utmi" will succeed.

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 45e5d6a..1ca7cf5 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -86,7 +86,7 @@
 #endif
 	}
 
-	if (!strcmp(phy_type, "utmi")) {
+	if (!strncmp(phy_type, "utmi", 4)) {
 #if defined(CONFIG_SYS_FSL_USB_INTERNAL_UTMI_PHY)
 		setbits_be32(&ehci->control, PHY_CLK_SEL_UTMI);
 		setbits_be32(&ehci->control, UTMI_PHY_EN);