hw/arm/boot: Honour CPU's address space for image loads

hw/arm/boot: Honour CPU's address space for image loads

Instead of loading kernels, device trees, and the like to
the system address space, use the CPU's address space. This
is important if we're trying to load the file to memory or
via an alias memory region that is provided by an SoC
object and thus not mapped into the system address space.

Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
Message-id: 20180220180325[email protected]