package/linknx: add license file

LICENSE has been added in version 0.0.1.32 with
https://github.com/linknx/linknx/commit/74671aa27931be40662c0266441c7470dc11d595

So add it to LINKNX_LICENSE_FILES as well as its hash

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/linknx/linknx.hash

@@ -1,2 +1,3 @@
 # Locally computed:
 sha256 635b8fbd3477fd7d85a95955b93f327cd5a389db80dc18cdae04de19a3a8a972  linknx-0.0.1.33.tar.gz
+sha256 c03cea027b4b40e4402fabd08557736727ec3d5bc54ad64ab6472de432198cad  LICENSE

package/linknx/linknx.mk

@@ -7,6 +7,7 @@
 LINKNX_VERSION = 0.0.1.33
 LINKNX_SITE = $(call github,linknx,linknx,$(LINKNX_VERSION))
 LINKNX_LICENSE = GPL-2.0+
+LINKNX_LICENSE_FILES = LICENSE
 LINKNX_INSTALL_STAGING = YES
 LINKNX_CONF_OPTS = \
 	--without-log4cpp \