ARM: 8560/1: errata: Workaround errata A12 825619 / A17 852421

The workaround for both errata is to set bit 24 in the diagnostic
register.  There are no known end-user bugs solved by fixing this
errata, but the fix is trivial and it seems sane to apply it.

The arguments for why this needs to be in the kernel are similar to the
arugments made in the patch "Workaround errata A12 818325/852422 A17
852423".

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>