sync arm64 pbuild resource limits with amd64; arm64 now builds some large

things and can easily exceed the previous 1.5GB limit.
(obviously, as with amd64, machines with less physical RAM won't cope with
building the largest ports).
ok deraadt phessler millert kettenis

src/etc/etc.arm64/login.conf

@@ -1,4 +1,4 @@
-# $OpenBSD: login.conf,v 1.5 2019/09/21 22:14:34 kurt Exp $
+# $OpenBSD: login.conf,v 1.6 2019/10/07 17:52:59 sthen Exp $
 
 #
 # Sample login.conf file.  See login.conf(5) for details.
@@ -92,9 +92,9 @@ authpf:\
 #
 pbuild:\
 	:datasize-max=infinity:\
-	:datasize-cur=1536M:\
+	:datasize-cur=6144M:\
 	:maxproc-max=1024:\
-	:maxproc-cur=256:\
+	:maxproc-cur=384:\
 	:tc=default:
 
 #