ar71xx: disable irq on reboot to fix hang issues (fixes #17839)

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

Backport of r42955

git-svn-id: svn://svn.openwrt.org/openwrt/branches/barrier_breaker@42956 3c298f89-4303-0410-b956-a3cf2f4a3e73
polarssl: do not build the unused programs

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

Backport of r42960

git-svn-id: svn://svn.openwrt.org/openwrt/branches/barrier_breaker@42961 3c298f89-4303-0410-b956-a3cf2f4a3e73