Makefile: Also blacklist J-Link SPI for DOS

libjaylink will probably never be available.

Change-Id: Ie9222f82e16fe4c76fe7dd0f9aac7de6a862ab98
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/33305
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/Makefile b/Makefile
index 4d23c39..e08a3f6 100644
--- a/Makefile
+++ b/Makefile
@@ -190,6 +190,12 @@
 else
 override CONFIG_CH341A_SPI = no
 endif
+# libjaylink is also not available for DOS
+ifeq ($(CONFIG_JLINK_SPI), yes)
+UNSUPPORTED_FEATURES += CONFIG_JLINK_SPI=yes
+else
+override CONFIG_JLINK_SPI = no
+endif
 endif
 
 # FIXME: Should we check for Cygwin/MSVC as well?