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>