arm: l2x0: add aurora related properties to OF binding

Aurora is a L2 Cache Controller designed to be compatible with the
L2x0 Cache Controller. L2X0 OF bindings are extended to support some
specificity of Aurora (no cache id part number available through
hardware, always write through mode, choice between outer cache and
system cache).

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Yehuda Yitschak <yehuday@marvell.com>
Tested-and-reviewed-by: Lior Amsalem <alior@marvell.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>