integratorcp: Don't migrate flash using vmstate_register_ram_global()

integratorcp: Don't migrate flash using vmstate_register_ram_global()

Instead of migrating the flash by creating the memory region
with memory_region_init_ram_nomigrate() and then calling
vmstate_register_ram_global(), just use memory_region_init_ram(),
which now handles migration registration automatically.

This is a migration compatibility break for the integratorcp
board, because the RAM region's migration name changes to
include the device path. This is OK because we don't guarantee
migration compatibility for this board.

Signed-off-by: Peter Maydell <[email protected]>
Message-id: 1500310341[email protected]