fdt: Properly handle "no-map" field in the memory region

Mark the memory region with NOMAP flag instead of completely removing it
from the memory blocks. That makes the FDT handling consistent with the EFI
memory map handling.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20210115114544.1830068-2-qperret@google.comSigned-off-by: Rob Herring <robh@kernel.org>

drivers/of/fdt.c

@@ -1147,7 +1147,7 @@ int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 					phys_addr_t size, bool nomap)
 {
 	if (nomap)
-		return memblock_remove(base, size);
+		return memblock_mark_nomap(base, size);
 	return memblock_reserve(base, size);
 }