dirtyjtag: Add DirtyJTAG programmer

Add a new programmer driver for the DirtyJTAG project (a USB-JTAG
firmware for STM32 MCUs).

Successfully tested with DirtyJTAG 1.4 running on an Olimex STM32-H103
development board and a SST25VF020B SPI flash chip.

Change-Id: Ic43e9a014ed7d04e429e73b30c9dcfdde1a78913
Signed-off-by: Jean THOMAS <virgule@jeanthomas.me>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/67878
Original-Reviewed-by: Felix Singer <felixsinger@posteo.net>
Original-Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/71492
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/programmer.h b/programmer.h
index 2047b8e..9217c0d 100644
--- a/programmer.h
+++ b/programmer.h
@@ -92,6 +92,7 @@
 extern const struct programmer_entry programmer_serprog;
 extern const struct programmer_entry programmer_stlinkv3_spi;
 extern const struct programmer_entry programmer_usbblaster_spi;
+extern const struct programmer_entry programmer_dirtyjtag_spi;
 
 int programmer_init(const struct programmer_entry *prog, const char *param);
 int programmer_shutdown(void);