serprog: allow to omit specifying a baud rate

On USB-based serial connections (VCP) the requested baud rate usually
does not matter (much). Remove the arbitrary restriction and use whatever
default values the OS/hardware provides.

Corresponding to flashrom svn r1907.

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