arm: Implement workaround for Cortex-A9 errata 845369

arm: Implement workaround for Cortex-A9 errata 845369

Under very rare timing circumstances, transitioning into streaming
mode might create a data corruption. Present on Two or more processors
or 1 core with ACP, all revisions. This erratum can be worked round
by setting bit[22] of the undocumented Diagnostic Control Register to 1.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Tom Rini <trini@konsulko.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Stefano Babic <sbabic@denx.de>