usb: chipidea: imx: add two samsung picophy parameters tuning implementation

These two parameters are used to improve USB signal for board level,
in this commit, we read it from the dtb, and write to related register
during the initialization.

Signed-off-by: Peter Chen <peter.chen@nxp.com>

drivers/usb/chipidea/ci_hdrc_imx.h

@@ -26,6 +26,8 @@ struct imx_usbmisc_data {
 	unsigned int ext_vbus:1; /* Vbus from exteranl event */
 	struct usb_phy *usb_phy;
 	enum usb_dr_mode available_role; /* runtime usb dr mode */
+	int emp_curr_control;
+	int dc_vol_level_adjust;
 };
 
 int imx_usbmisc_init(struct imx_usbmisc_data *data);