grub: add download mirrors

Add three download mirrors for 'grub', as the Makefile currently defines only
one download location.

@GNU can not be used, as the most recent version of 'grub' is not available
at the general GNU mirrors, and can only be found at the "gnu-alpha" mirrors.

Signed-off-by: Hannu Nyman <hannu.nyman at iki.fi>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 45909

package/boot/grub2/Makefile

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2006-2010 OpenWrt.org
+# Copyright (C) 2006-2015 OpenWrt.org
 #
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
@@ -13,7 +13,10 @@ PKG_VERSION:=2.02~beta2
 PKG_RELEASE:=1
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
-PKG_SOURCE_URL:=http://alpha.gnu.org/gnu/grub
+PKG_SOURCE_URL:=http://alpha.gnu.org/gnu/grub \
+	http://gnualpha.uib.no/grub/ \
+	http://mirrors.fe.up.pt/pub/gnu-alpha/grub/ \
+	http://www.nic.funet.fi/pub/gnu/alpha/gnu/grub/
 PKG_MD5SUM:=be62932eade308a364ea4bbc91295930
 
 HOST_BUILD_PARALLEL:=1