drivers/Makefile.am: Fix libjaylink integration

Include libjaylink in DIST_SUBDIRS only if J-Link driver is enabled.

Change-Id: Ib32bb6a5d8fe9bb6e93d968802733eb4973f2c25
Signed-off-by: Marc Schink <openocd-dev@marcschink.de>
Reviewed-on: http://openocd.zylin.com/3529


Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>

src/jtag/drivers/Makefile.am

@@ -167,8 +167,10 @@ noinst_HEADERS = \
 
 DIST_SUBDIRS = usb_blaster
 
+if JLINK
 if INTERNAL_LIBJAYLINK
 DIST_SUBDIRS += libjaylink
 endif
+endif
 
 MAINTAINERCLEANFILES = $(srcdir)/Makefile.in