power: charger: get the current information from usb-otg

usb_otg is able to know what kind of charger is connected like as
USB, TA and  Slimport. And we can decide the max charging current
by cable type. pm8921-charger is able to use this information.

And unplug_check_worker has some problem. Wrong charging current
might set as 100mA even thought USB charger can be set by max 500mA.
It cause very slow charging.

msg_otg didn't use power supply api properly due to not supported
some POWER_SUPPLY_PROPs in pm8921-charger.c. It's also fixed.

Change-Id: I86661fbe38e3db5522caab6ff316c0100f87fe0d
diff --git a/drivers/usb/otg/msm_otg.c b/drivers/usb/otg/msm_otg.c
index db6a246..4df4060 100644
--- a/drivers/usb/otg/msm_otg.c
+++ b/drivers/usb/otg/msm_otg.c
@@ -1083,6 +1083,8 @@
 		return 0;
 	}
 	/* Set max current limit */
+	dev_info(motg->phy.dev, "current: %d -> %d (mA)\n",
+			motg->cur_power, mA);
 	if (power_supply_set_current_limit(psy, 1000*mA))
 		goto psy_not_supported;