libxslt: update xsltproc depends

libxml2 can be removed as libxslt already depends on it.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

libs/libxslt/Makefile

@@ -54,7 +54,7 @@ endef
 define Package/xsltproc
   SECTION:=utils
   CATEGORY:=Utilities
-  DEPENDS:=+libxml2 +libxslt +libexslt
+  DEPENDS:=+libxslt +PACKAGE_xsltproc:libexslt
   TITLE:=Gnome XSLT xsltproc Utility
   URL:=http://xmlsoft.org/XSLT/
 endef