phy: msm: usb: Check VBUS state before accessing registers in suspend

Currently driver is checking for VBUS state after accessing register
in msm_otg_suspend() routine. In case of CDP, there will be race between
msm_otg_suspend() and driving DP pulse. This could cause accessing
register in msm_otg_suspend() while clocks are off as part of sequence
to drive pulse on D+ line and later it is checking for VBUS state high
to abort suspend sequence. Hence fix it by checking for VBUS state
before accessing registers in msm_otg_suspend().

Change-Id: I95ad5339b21647e3971908d15f2eabe0c6311800
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>