usb: phy: snps: Enable auto-resume during host mode bus suspend

Currently driver is enabling auto-resume irrespective of whether
peripheral is connected to the host or not. Adding PHY flags before
enabling auto-resume ensures that some peripheral must have been
connected before bus suspend. This change enables auto-resume only
during host mode real bus suspend.

Change-Id: Ifed2f0a773ace31738628a988062f96e92efad44
Signed-off-by: Pratham Pratap <prathampratap@codeaurora.org>