usb: ci13xxx_udc: Send suspend event notification to udc driver

Add HSIC power management to support HSIC core Low Power Mode and
integrate it with System PM and Runtime PM mechanisms.

Change-Id: Id87d5740e7f229e599f8f6bb17a70ac1d8078bf4
Signed-off-by: Ofir Cohen <ofirc@codeaurora.org>
[sboyd: Only take ci13xxx_udc part]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>