USB: OTG: msm: Add support for power management

Implement runtime and system pm ops to put hardware into low power
mode (LPM). As part of LPM, USB clocks are turned off, PHY is put
into suspend state and PHY comparators are turned off if VBUS/Id
notifications are not required from PHY.

Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/usb/msm_hsusb.h

@@ -88,6 +88,8 @@ struct msm_otg_platform_data {
  * @regs: ioremapped register base address.
  * @inputs: OTG state machine inputs(Id, SessValid etc).
  * @sm_work: OTG state machine work.
+ * @in_lpm: indicates low power mode (LPM) state.
+ * @async_int: Async interrupt arrived.
  *
  */
 struct msm_otg {
@@ -103,6 +105,8 @@ struct msm_otg {
 #define B_SESS_VLD	1
 	unsigned long inputs;
 	struct work_struct sm_work;
+	atomic_t in_lpm;
+	int async_int;
 };
 
 #endif