arm64: mm: Move reserve_crashkernel() into mem_init()

crashkernel might reserve memory located in ZONE_DMA. We plan to delay
ZONE_DMA's initialization after unflattening the devicetree and ACPI's
boot table initialization, so move it later in the boot process.
Specifically into bootmem_init() since request_standard_resources()
depends on it.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Link: https://lore.kernel.org/r/20201119175400.9995-2-nsaenzjulienne@suse.deSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/mm/init.c

@@ -393,8 +393,6 @@ void __init arm64_memblock_init(void)
 	else
 		arm64_dma32_phys_limit = PHYS_MASK + 1;
 
-	reserve_crashkernel();
-
 	reserve_elfcorehdr();
 
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
@@ -434,6 +432,12 @@ void __init bootmem_init(void)
 	sparse_init();
 	zone_sizes_init(min, max);
 
+	/*
+	 * request_standard_resources() depends on crashkernel's memory being
+	 * reserved, so do it here.
+	 */
+	reserve_crashkernel();
+
 	memblock_dump_all();
 }