USB: OTG: msm: Add PMIC VBUS notification support for peripheral only mode

Add PMIC VBUS notification support for peripheral only mode and
allow PHY retention and power collapse.  This patch also makes
changes to probe function to request PMIC ID IRQ in only OTG mode.

CRs-fixed: 330349
Change-Id: I4a5a6c50b0a3b56dcf78aea5b23499a264b3c9d5
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>