USB: Prevent USB to enter LPM if qdss connect work is not processed

For usb cable connect in qdss composition, qdss driver will queue qdss
connect work as part of qdss_set_alt(). As part of multiple usb connect
and disonnect, USB can enter low power mode before the qdss connect work
is compeleted. This results in crash while acessing usb registers during
processing of the qdss connect work as USB clocks are off.

Fix this issue by ensuring that if qdss connect work is scheduled, then
do not allow USB to enter low power mode before qdss connect work is
completely processed. To implement this, use flag qdss_usb_active. When
usb is connected, set flag qdss_usb_active to true in qdss_set_alt().
When qdss connect work is already processed, then set the flag
qdss_usb_active to false. Further, add check in msm_bam_usb_lpm_ok()
and check if usb qdss connect work is scheduled but not completely
processed, then do not allow USB to enter low power mode.

CRs-Fixed: 718015
Change-Id: Id3d0751a01b96fb3a4f9bbb9fe3adbe25228618e
Signed-off-by: Saket Saurabh <ssaurabh@codeaurora.org>