ARM: 7345/1: errata: update workaround for A9 erratum #743622

Erratum #743622 affects all r2 variants of the Cortex-A9 processor, so
ensure that the workaround is applied regardless of the revision.

Cc: <stable@vger.kernel.org>
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>