usb: dwc3-msm: Add additional debugging messages

Add additional log event messages to aid in debugging. In
particular, add to places where runtime PM is potentially
racy. Also increase log buffer size from 128 to 2048 entries.

Change-Id: Ie68e9b9c000271e03f415fbfd0076151bc595729
Signed-off-by: Jack Pham <jackp@codeaurora.org>