drivers: add RmNet snapshot

Adds snapshot of main RmNet driver as of commit 5cc0f9c4
("drivers: net: rmnet: introduce rmnet traces")
and auxiliary DFC/WDA drivers as of commit 1e2e505e ("soc:
qcom: dfc: Enable flow after ps work is marked as inactive").

Additional changes required by checkpatch/upgrade process:
	- update all licenses to SPDX format.
	- merge rmnet_trace.h into trace/events/rmnet.h.
	- minor formatting cleanup.
	- update type signature for rmnet_add_bridge() and
	  rmnet_vnd_select_queue().
	- fix use of powersave qmi APIs outside of #ifdefs.
	- update DFC QMI messages to use new field names.
	- update DFC traces to fit within 80 char limit.
	- replace DFC/WDA module params with equivalent
	  netlink messages.

Change-Id: I9382c099e3eb21704d3b029e2f1c73ab5c1511cc
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>