Add initial J-Link SPI programmer

Tested with SEGGER J-Link EDU, Flasher ARM and flash chip W25Q16.V.

Change-Id: Ie03a054a75457ec9e1cab36ea124bb53b10e8d7e
Signed-off-by: Marc Schink <flashrom-dev@marcschink.de>
Reviewed-on: https://review.coreboot.org/c/28087
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/README b/README
index b5ed946..4e7bd4f 100644
--- a/README
+++ b/README
@@ -50,6 +50,7 @@
  * pciutils+libpci (if you want support for mainboard or PCI device flashing)
  * libusb (if you want FT2232, Dediprog or USB-Blaster support)
  * libftdi (if you want FT2232 or USB-Blaster support)
+ * libjaylink (if you want support for SEGGER J-Link and compatible devices)
 
 Linux et al: