usb: phy-msm-usb: don't power collapse PHY during peripheral bus suspend

ALLOW_PHY_POWER_COLLAPSE LPM capability flag is set for the targets which
can receive VBUS/ID notifications from PMIC. When this flag is set,
the PHY is power collapsed during LPM. Avoid this for the peripheral bus
suspend case.

Change-Id: I838724a5526fe22376d2199fa454a570e1cadf6e
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>