arm/vexpress: use memdev for RAM
replace it with memdev allocated MemoryRegion. The later is
initialized by generic code, so board only needs to opt in
to memdev scheme by providing
MachineClass::default_ram_id
and using MachineState::ram instead of manually initializing
RAM memory region.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <
20200219160953.13771-33-imammedo@redhat.com>