UDS: move from drivers/net/ to net/

Change-Id: I53992b205e767a77c7b3c868a38c7f3d772a4ed3
etc/usr/rc: fix argument passing for net drivers

The expected argument name would include the instance number, which
is not only redundant in many cases (FOOETHn_n=arg.., "n" being the
instance number) and conflicted with what netconf(8) does, but some
drivers need to be able to see the arguments for all instances of its
driver type--for example, dp8390 needs to know how many earlier
instances have been configured to use PCI.

Change-Id: I4830b823352722f554a032979464aba8b08fc166
dp8390: update, allow default port and IRQ

Bochs has switched from port base 0x240 to 0x300 for its default
NE2000 ISA configuration, and QEMU is using the same settings.

Change-Id: Ide6cdb14321eb4324d0bf6d6314c5970b3493e95