arm: memory: Replace memory_region_init_ram with memory_region_allocate_system_memory

arm: memory: Replace memory_region_init_ram with memory_region_allocate_system_memory

Commit 0b183fc871:"memory: move mem_path handling to
memory_region_allocate_system_memory" split memory_region_init_ram and
memory_region_init_ram_from_file. Also it moved mem-path handling a step
up from memory_region_init_ram to memory_region_allocate_system_memory.

Therefore for any board that uses memory_region_init_ram directly,
-mem-path is not supported.

Fix this by replacing memory_region_init_ram with
memory_region_allocate_system_memory.

Signed-off-by: Dirk Mueller <dmueller@suse.com>
Message-id: CAL5wTH4UHYKpJF=dLJfFzxpufjY189chnCow47-ySuLf8GLbug@mail.gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>