mfd: omap-usb-tll: Configure ULPIAUTOIDLE

The idle mode needs to be only disabled for UTMIAUTOIDLE while
ULPIAUTOIDLE can be enabled.

This matches the TLL_CHANNEL_CONF_i register configuration for ehci-tll
in the Motorola Linux kernel tree for Wrigley 3G LTE modem on droid 4
and the modem still stays responsive.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/omap-usb-tll.c

@@ -373,12 +373,13 @@ int omap_tll_init(struct usbhs_omap_platform_data *pdata)
 			} else if (pdata->port_mode[i] ==
 					OMAP_EHCI_PORT_MODE_TLL) {
 				/*
-				 * Disable AutoIdle, BitStuffing
-				 * and use SDR Mode
+				 * Disable UTMI AutoIdle, BitStuffing
+				 * and use SDR Mode. Enable ULPI AutoIdle.
 				 */
 				reg &= ~(OMAP_TLL_CHANNEL_CONF_UTMIAUTOIDLE
 					| OMAP_TLL_CHANNEL_CONF_ULPIDDRMODE);
 				reg |= OMAP_TLL_CHANNEL_CONF_ULPINOBITSTUFF;
+				reg |= OMAP_TLL_CHANNEL_CONF_ULPI_ULPIAUTOIDLE;
 			} else if (pdata->port_mode[i] ==
 					OMAP_EHCI_PORT_MODE_HSIC) {
 				/*