ARM: 8556/1: on a generic DT system: do not touch l2x0

Set no bits, mask all bits in the AUX l2x0 register for the
default DT ARM system: if anything needs to be modified, it
should be done using DT bindings.
Suggested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/devtree.c

@@ -213,6 +213,8 @@ const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
 
 #if defined(CONFIG_ARCH_MULTIPLATFORM) || defined(CONFIG_ARM_SINGLE_ARMV7M)
 	DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
+		.l2c_aux_val = 0x0,
+		.l2c_aux_mask = ~0x0,
 	MACHINE_END
 
 	mdesc_best = &__mach_desc_GENERIC_DT;