of/fdt: use memblock_virt_alloc for early alloc

memblock_virt_alloc() works for both memblock and bootmem, so use it and
make early_init_dt_alloc_memory_arch a static function. The arches using
bootmem define early_init_dt_alloc_memory_arch as either:

__alloc_bootmem(size, align, __pa(MAX_DMA_ADDRESS))

or:

alloc_bootmem_align(size, align)

Both of these evaluate to the same thing as does memblock_virt_alloc for
bootmem. So we can disable the arch specific functions by making
early_init_dt_alloc_memory_arch static and they can be removed in
subsequent commits.

Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 7db5353..84aa9d6 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -11,6 +11,7 @@
 #include <linux/crc32.h>
 #include <linux/kernel.h>
 #include <linux/initrd.h>
+#include <linux/bootmem.h>
 #include <linux/memblock.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
@@ -1180,14 +1181,6 @@ int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 	return memblock_reserve(base, size);
 }
 
-/*
- * called from unflatten_device_tree() to bootstrap devicetree itself
- * Architectures can override this definition if memblock isn't used
- */
-void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
-{
-	return __va(memblock_alloc(size, align));
-}
 #else
 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
 {
@@ -1206,14 +1199,13 @@ int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
 		  &base, &size, nomap ? " (nomap)" : "");
 	return -ENOSYS;
 }
-
-void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
-{
-	WARN_ON(1);
-	return NULL;
-}
 #endif
 
+static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+	return memblock_virt_alloc(size, align);
+}
+
 bool __init early_init_dt_verify(void *params)
 {
 	if (!params)