dwc3: msm: Overwrite return value of pm_runtime_suspend() if > 0

Display driver calls callback to USB PD driver to release SS lanes
if it figures out to support high bandwidth transfers. Due to this,
USB PD driver sends notification to dwc3_msm driver to stop host mode
and start host mode again in high speed mode. Stop host mode already
takes care of putting mdwc device in suspend state. if mdwc device is
already suspended, pm_runtime_suspend() API returns 1 and same return
value is delegated to USB PD driver and then to display driver. This
gives false impression that SS lanes are not released, which is not
the case. Hence fix the issue by overwriting return value of
pm_runtime_suspend() API if it returns 1.

Change-Id: I6a6380a1c6fa93905711ea64e3d32d247afd1db8
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>