USB: EHCI: Notify HCD about HNP enabled port suspend

Introduce a new callback method for HCD to receive notification
from EHCI core that HNP enabled port is suspended.  HCD may call
otg_start_hnp() to kick OTG state machine. Typically OTG driver
starts A_AIDL_BDIS timer and wait for B-device disconnection.

Change-Id: I1dc02c3ac9cc39ce3f45a4ff05a389fc36e4e952
Signed-off-by: Pavankumar Kondeti <pkondeti@qualcomm.com>