usb: dwc3: Perform core soft reset when erratic event occurs

Sometimes after receiving erratic event controller is generating
interrupt storm even if driver acknowledges events generated
after erratic events. This causes watchdog bark. Hence assert
core soft reset and wait until erratic event recovery is
performed which brings the core out of reset for normal
operation.

CRs-Fixed: 752945
Change-Id: Ia05bd69404a316ddba5ef205e7495ac50e1815a6
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>