This patch disables outer cache sync in PL310 driver by adding "arm,io-coherent" property. In addition to the previous patches it was the last bit needed for enabling proper operation of Armada 38x SoCs with the IO cache coherency. Submitted by: Michal Mazur <mkm@semihalf.com> Obtained from: Semihalf Sponsored by: Stormshield Reviewed by: mmel Differential revision: https://reviews.freebsd.org/D11204