Refine support for SST25VF family.

 - Reorder some models and refine comments.
 - Add SST25VF512A:
   AAI is available but with an uncommon opcode (0xAF). Fully tested
   with Bus Pirate 3.5 running 6.2 beta firmware by Cory.
 - Add SST25VF020 and SST25VF020B.

Signed-off-by: Cory Henderson <dcoryh192@gmail.com>
Signed-off-by: Stefan Tauner <stefan.tauner@student.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@student.tuwien.ac.at>

git-svn-id: svn://flashrom.org/flashrom/trunk@1758 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
serial: use internal_delay() for timeouts.

Using programmer_delay() for timeouts in serial writes could cause a
(theoretically) endless recursion if serial communication is used to
send the programmer the delay command to be executed on the programmer
instead of the host which fails again, following a timeout which
sends...

Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Acked-by: Stefan Tauner <stefan.tauner@student.tuwien.ac.at>

git-svn-id: svn://flashrom.org/flashrom/trunk@1759 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1