powerpc/pseries: Fix ibm,client-architecture comment

We specify a 64MB RMO, but the comment says 128MB.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/powerpc/kernel/prom_init.c

@@ -614,7 +614,7 @@ static unsigned char ibm_architecture_vec[] = {
 	W(0xffffffff),			/* virt_base */
 	W(0xffffffff),			/* virt_size */
 	W(0xffffffff),			/* load_base */
-	W(64),				/* 128MB min RMA */
+	W(64),				/* 64MB min RMA */
 	W(0xffffffff),			/* full client load */
 	0,				/* min RMA percentage of total RAM */
 	48,				/* max log_2(hash table size) */