perl: Update license identifiers to match SPDX

Signed-off-by: Marcel Denia <naoir@gmx.net>

lang/perl/Makefile

@@ -22,7 +22,7 @@ PKG_SOURCE_URL:=ftp://ftp.cpan.org/pub/CPAN/src/5.0 \
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_MD5SUM:=406ec049ebe3afcc80d9c76ec78ca4f8
 
-PKG_LICENSE:=GPLv1+ ARTISTIC
+PKG_LICENSE:=GPL-1.0+ Artistic-1.0-Perl
 PKG_LICENSE_FILES:=Copying Artistic README
 PKG_MAINTAINER:=Marcel Denia <naoir@gmx.net>