usb: chipidea: add ci_hdrc_enter_lpm API

This API is used to let the PHY enter/leave low power mode.
Before the controller going to work(at probe/resume), it needs to let
the PHY leave low power mode.
After the controller stopping working(at remove/suspend), it needs to
let the PHY enter low power mode to save power consumption.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/chipidea/bits.h b/drivers/usb/chipidea/bits.h
index 464584c..a857131 100644
--- a/drivers/usb/chipidea/bits.h
+++ b/drivers/usb/chipidea/bits.h
@@ -48,6 +48,7 @@
 #define PORTSC_SUSP           BIT(7)
 #define PORTSC_HSP            BIT(9)
 #define PORTSC_PTC            (0x0FUL << 16)
+#define PORTSC_PHCD(d)	      ((d) ? BIT(22) : BIT(23))
 /* PTS and PTW for non lpm version only */
 #define PORTSC_PTS(d)						\
 	(u32)((((d) & 0x3) << 30) | (((d) & 0x4) ? BIT(25) : 0))