Caching dates is never a good idea ;-)

Fixes: 7253b85c ("ARM: 7541/1: Add ARM ERRATA 775420 workaround")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>