libdmtx: add license information

Signed-off-by: Frank Hunleth <fhunleth@troodon-software.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libdmtx/libdmtx.mk

@@ -6,6 +6,8 @@
 
 LIBDMTX_VERSION = 0.7.4
 LIBDMTX_SITE = http://downloads.sourceforge.net/project/libdmtx/libdmtx/$(LIBDMTX_VERSION)
+LIBDMTX_LICENSE = BSD-2c or Special Permission
+LIBDMTX_LICENSE_FILES = LICENSE
 LIBDMTX_INSTALL_STAGING = YES
 
 $(eval $(autotools-package))