some machines require pretty massive physical address space maps

Reference: /n/atom/patch/applied2013/adrbig
Date: Tue Dec 17 17:39:04 CET 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/adr.c	Tue Dec 17 17:38:50 2013
+++ /sys/src/nix/k10/adr.c	Tue Dec 17 17:38:50 2013
@@ -19,7 +19,7 @@
 
 static struct {
 	Lock;
-	Adrmap	map[200];
+	Adrmap	map[400];
 	int	nmap;
 	uvlong	pagecnt[Mlast];
 } adr;