Add Altera USB-Blaster SPI programmer.

Adds support for the Altera USB-Blaster programming dongle in Active
Serial (AS) mode. Tested on both original product and a clone dongle.

Signed-off-by: James Laird <jhl@mafipulation.org>
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Signed-off-by: Stefan Tauner <stefan.tauner@student.tuwien.ac.at>
Acked-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Acked-by: Stefan Tauner <stefan.tauner@student.tuwien.ac.at>

git-svn-id: svn://flashrom.org/flashrom/trunk@1658 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1