Add an ARM CPU property for the reset value of hivecs as it is a
board/SoC configurable setting.

The existence of the property is conditional on the ARM CPU not being M
class.
Signed-off-by: NAntony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: b04216c6bda4bd163f44a55bba552d0e8267481f.1387160489.git.peter.crosthwaite@xilinx.com
[ PC Changes:
 * Elaborated commit message
 * refactored to use qdev_property_add_static
]
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>