ARM: l2c: ux500: don't try to change the L2 cache auxiliary control register

ux500 can't change the auxiliary control register, so there's no point
passing values to try and modify it to the l2x0 init functions.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>