arm64: Add workaround for Cavium erratum 27456

arm64: Add workaround for Cavium erratum 27456

On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI
instructions may cause the icache to become corrupted if it contains
data for a non-current ASID.

This patch implements the workaround (which invalidates the local
icache when switching the mm) by using code patching.

Signed-off-by: Andrew Pinski <[email protected]>
Signed-off-by: David Daney <[email protected]>
Reviewed-by: Will Deacon <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>