Change etcupdate tests to return 1 on test failures.

This is a prerequisite for hooking these tests into the test suite.  And,
fortunately, all tests seem to pass!
Add Makefile missed in r263220.
* Add ethernet MAC configuration from the EEPROM for arge0/arge1
* The AR9344 switch has 5 ports in use, not four.

Tested:

* DB120 reference board