configure: Use same case for libjaylink as for other libs

Change-Id: I60d91a0543d9b8c580254cdc5f04b2e60209b98b
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/3868


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