Add support for all 4 possible channels to the ft2232_spi programmer

Add a check to validate the selected channel/interface, which not even
libftdi seems to do yet.
This patch changes default behavior: the new default channel/interface is A.
Also, this patch uses the word 'channel' in addition or in place of 'interface'
where possible without too much hassle because it is the term FTDI uses.

Corresponding to flashrom svn r1608.

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
2 files changed