serprog: Move content of programmer specific header to C file

Move the programmer specific code into serprog.c and remove its related
header file.

Change-Id: I5c65f43db200129489d487ff948daa08bd0e92fa
Signed-off-by: Felix Singer <felix.singer@secunet.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/58300
Original-Reviewed-by: Thomas Heijligen <src@posteo.de>
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
2 files changed