Bus space handle type for mips

[Martin Husemann <martin%duskware.de@localhost>]

This patch makes bus_space_handle_t unsigned again (as it was before the 
partial mips64 merges where it changed from u_long to intptr_t).

This unbreaks PCI on alchemy boards for me. I don't see why the handle
should be a signed value - am I missing something?

OK to commit?

Martin
(of course it still can't exec init, hi Matt!)

Index: bus_space.h
===================================================================
RCS file: /cvsroot/src/sys/arch/mips/include/bus_space.h,v
retrieving revision 1.5
diff -c -u -r1.5 bus_space.h
--- bus_space.h 14 Dec 2009 00:46:04 -0000      1.5
+++ bus_space.h 6 Jun 2010 21:12:18 -0000
@@ -116,7 +116,7 @@
  * Access methods for bus space.
  */
 typedef struct mips_bus_space *bus_space_tag_t;
-typedef intptr_t bus_space_handle_t;
+typedef uintptr_t bus_space_handle_t;
 #define        PRIxBSH         PRIxPTR
 
 struct mips_bus_space {