usb: dwc3: Add debug events to track pm runtime calls

There are no exisiting debug events which track the
pm_runtime_get/get_sync and pm_runtime_put/put_sync calls.
This helps to debug race conditions occuring during
PM runtime and system suspend/resume.

CRs-fixed: 722712
Change-Id: I4841d62a0140acc9d635fd27d64311ea16aad163
Signed-off-by: Azhar Shaikh <azhars@codeaurora.org>