USB: dwc3: msm: Fix bug during STM enable/disable for QDSS

commit "I0fdc5d703b3fd445e83226534f07743461c96f4c:usb: dwc3-msm:
remove use of global context variable (DBM)" is required for adding
support multiple instances in dwc3-msm driver. This added an incorrect
condition check in the driver before reinitiating USB reconnection
for STM enable/disable. Due to this, QDSS doesn't work when STM tracing
is disabled and enabled. Hence Fix this issue by using proper check.

CRs-Fixed: 523344
Change-Id: I6302396c7bf03cd2313e5d571e0aef51648a2258
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>