Add 32-bit compatibility to device-tree CPU nodes

Add 32-bit compatibility to device-tree CPU nodes

The 32-bit DT parser in Linux doesn't understand 'reg' properties with
two cells, in a CPU node. Since the boot-wrapper always sets the upper
bits to 0, we can restrict that size to one cell.

The parser also requires the device_type property to be present. This is
the case for arm64 as well, but it only fails when the patched device-tree
doesn't have any CPU node to begin with. Add device_type unconditionally.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>