USB: msm_otg: Don't allow TCXO shutdown in host bus suspend

Currently otg driver is voting to allow TCXO shutdown in host
bus suspend due to which devices connected in system suspend
are not getting detected. Hence don't allow TCXO shutdown in
host bus suspend.

As long term solution, need HW rework for detecting connecting
devices in host mode during system suspend. This is required to
route D+ and D- lines to MPM for monitoring interrupt during
system suspend.

CRs-Fixed: 366111
Change-Id: Ic478a0e327b104eec64b5cfe2bd1f9369f8ef72e
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>