bootconfig: Allocate xbc_nodes array dynamically

To reduce the large static array from kernel data, allocate
xbc_nodes array dynamically only if the kernel loads a
bootconfig.

Note that this also add dummy memblock.h for user-spacae
bootconfig tool.

Link: http://lkml.kernel.org/r/158108569699.3187.6512834527603883707.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tools/bootconfig/include/linux/memblock.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _XBC_LINUX_MEMBLOCK_H
+#define _XBC_LINUX_MEMBLOCK_H
+
+#include <stdlib.h>
+
+#define __pa(addr)	(addr)
+#define SMP_CACHE_BYTES	0
+#define memblock_alloc(size, align)	malloc(size)
+#define memblock_free(paddr, size)	free(paddr)
+
+#endif