all boards were switched to using memdev backend for main RAM,
so we can drop no longer used memory_region_allocate_system_memory()
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200219160953.13771-73-imammedo@redhat.com>