Add more license tags with SPDX identifiers

Note, that licensing stuff is a nightmare: many packages does not clearly
state their licenses, and often multiple source files are simply copied
together - each with different licensing information in the file headers.

I tried hard to ensure, that the license information extracted into the OpenWRT's
makefiles fit the "spirit" of the packages, e.g. such small packages which
come without a dedicated source archive "inherites" the OpenWRT's own license
in my opinion.

However, I can not garantee that I always picked the correct information
and/or did not miss license information.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

SVN-Revision: 43155

package/boot/fconfig/Makefile

@@ -15,6 +15,9 @@ PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=http://andrzejekiert.ovh.org/software/fconfig/
 PKG_MD5SUM:=dac355e9f2a0f48c414c52e2034b6346
 
+PKG_LICENSE:=GPL-2.0+
+PKG_LICENSE_FILES:=
+
 PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)
 
 include $(INCLUDE_DIR)/package.mk