elf_ops.h: Use address_space_write() to write memory

elf_ops.h: Use address_space_write() to write memory

Currently the load_elf function in elf_ops.h uses
cpu_physical_memory_write() to write the ELF file to
memory if it is not handling it as a ROM blob. This
means we ignore the AddressSpace that the function
is passed to define where it should be loaded.
Use address_space_write() instead.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181122172653.3413-4-peter.maydell@linaro.org