net: documentation: build a directory structure for drivers

Documentation/networking/ is full of cryptically named files with
driver documentation.  This makes finding interesting information
at a glance really hard.  Move all those files into a directory
called device_drivers (since not all drivers are for device) and
fix up references.

RFC v0.1 -> RFC v1:
 - also add .txt suffix to the files which are missing it (Quentin)

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: David Ahern <dsahern@gmail.com>
Acked-by: Henrik Austad <henrik@austad.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: Jakub Kicinski

Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt

@@ -10,7 +10,7 @@ such as network interfaces, crypto accelerator instances, L2 switches,
 etc.
 
 For an overview of the DPAA2 architecture and fsl-mc bus see:
-Documentation/networking/dpaa2/overview.rst
+Documentation/networking/device_drivers/freescale/dpaa2/overview.rst
 
 As described in the above overview, all DPAA2 objects in a DPRC share the
 same hardware "isolation context" and a 10-bit value called an ICID

Documentation/networking/3c509.txt renamed to Documentation/networking/device_drivers/3com/3c509.txt

@@ -1,4 +1,4 @@
-Documentation/networking/vortex.txt
+Documentation/networking/device_drivers/3com/vortex.txt
 Andrew Morton
 30 April 2000