of:of_numa: remove unused macro

By reading the code, I found the marco DEFAULT_NODE is never
referenced in the code. Just remove it.

Signed-off-by: Ba Jing <bajing@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20241008060645.36071-1-bajing@cmss.chinamobile.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Author: Ba Jing

drivers/of/of_numa.c

@@ -14,9 +14,6 @@
 
 #include <asm/numa.h>
 
-/* define default numa node to 0 */
-#define DEFAULT_NODE 0
-
 /*
  * Even though we connect cpus to numa domains later in SMP
  * init, we need to know the node ids now for all cpus.