drivers/net/ethernet: Add ethernet dir and config option

This is the initial patch to organize the drivers/net directory
structure and networking device driver config options.  This patch
does the following:
  - add drivers/net/ethernet/Kconfig
  - integrate the new files into the existing config

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
new file mode 100644
index 0000000..0d21dda
--- /dev/null
+++ b/drivers/net/ethernet/Makefile
@@ -0,0 +1,3 @@
+#
+# Makefile for the Linux network Ethernet device drivers.
+#