mvebu: add support for the Linksys boot counter

The u-boot boot counter was never reset after a successful boot,
which sometimes could make some variables become out of sync.
This patch adds support for the boot counter and enables
auto_recovery unconditionally.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Signed-off-by: Rob Mosher <nyt-openwrt@countercultured.net>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@46690 3c298f89-4303-0410-b956-a3cf2f4a3e73