grub2: update to 2.02-beta2, fixes mac os x 10.9 support (and many other things)

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39889 3c298f89-4303-0410-b956-a3cf2f4a3e73