powerpc/44x: Fix build error on currituck platform

The MPIC_PRIMARY define was recently made "default" and the meaning was
inverted to MPIC_SECONDARY.  This causes compile errors in currituck now, so
fix it to the new manner of allocating mpics.
Signed-off-by: Josh Boyer <jwboyer@gmail.com>

arch/powerpc/platforms/44x/currituck.c

@@ -83,7 +83,7 @@ static void __init ppc47x_init_irq(void)
 		 * device-tree, just pass 0 to all arguments
 		 */
 		struct mpic *mpic =
-			mpic_alloc(np, 0, MPIC_PRIMARY, 0, 0, " MPIC     ");
+			mpic_alloc(np, 0, 0, 0, 0, " MPIC     ");
 		BUG_ON(mpic == NULL);
 		mpic_init(mpic);
 		ppc_md.get_irq = mpic_get_irq;