usb: dwc3: Add logging for ep0 map/unmap requests

Log the ep0 dma map/unmap request  in the IPC log buffer
for debugging SMMU faults.

Logs can be accessed using below command
cat /sys/kernel/debug/ipc_logging/a600000.dwc3.ep_events/log.

Change-Id: If5587b8ba59451593968999b59cd61f2a469fe1c
Signed-off-by: Elson Roy Serrao <eserrao@codeaurora.org>