Allow run_remote_tests to learn board instead of default board

Allow run_remote_tests to learn board instead of default board

If no board is specified for run remote tests,
learn board from device under test instead of using
default board.

BUG=none
TEST= ./run_remote_tests.sh without --board. Verify detects board and
deploys appropriate version for that board.
./run_remote_test.sh with --board x86-mario. Verify that it deploys
that specific board, regardless of target.

Change-Id: I6e71f0f1bf4b2bcfcd3430b29adc16531c6a8c81
Signed-off-by: Benson Leung <bleung@chromium.org>;
Signed-off-by: Chris Sosa <sosa@chromium.org>;

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=393c17b

[Benson Leung, 2011-02-24 01:05:53]

Mandeep helped me fix this issue with run_remote_tests. I forgot to add --board
to specify my board and it picked the wrong one and didn't pull in my changes.

[sosa, 2011-02-24 01:27:32]

LGTM!