ARM: 8890/1: l2x0: add marvell,ecc-enable property for aurora

The aurora cache on the Marvell Armada-XP SoC supports ECC protection
for the L2 data arrays. Add a "marvell,ecc-enable" device tree property
which can be used to enable this.

[jlu@pengutronix.de: use aurora specific define AURORA_ACR_ECC_EN]

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>