usb: chipidea: imx: set power polarity

This patch adds support to set the power line polarity for i.MX SoCs.

To let the USB controller control the power it may be necessary to
configure the polarity of the power line. So far the polarity was
configured by Bootloader or alternatively the power line was muxed
as gpio and driven by a regulator.

Also make use of of_property_read_bool.

Signed-off-by: Philipp Puschmann <philipp.puschmann@emlix.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/chipidea/ci_hdrc_imx.h

@@ -18,6 +18,7 @@ struct imx_usbmisc_data {
 	/* true if dt specifies polarity */
 	unsigned int oc_pol_configured:1;
 
+	unsigned int pwr_pol:1; /* power polarity */
 	unsigned int evdo:1; /* set external vbus divider option */
 	unsigned int ulpi:1; /* connected to an ULPI phy */
 	unsigned int hsic:1; /* HSIC controlller */