xen/perfc: Trim includes

This is mostly for the removal of xen/lib.h and xen/smp.h from perfc.h.  All
that is needed is xen/macros.h.

Trim and sort the includes for perfc.c too.  There's no need for smp.h,
keyhandler.h or mm.h, but cpumask.h is needed.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/common/perfc.c

@@ -1,13 +1,12 @@
 
+#include <xen/cpumask.h>
 #include <xen/errno.h>
-#include <xen/lib.h>
-#include <xen/smp.h>
-#include <xen/time.h>
-#include <xen/perfc.h>
-#include <xen/keyhandler.h> 
-#include <xen/spinlock.h>
-#include <xen/mm.h>
 #include <xen/guest_access.h>
+#include <xen/lib.h>
+#include <xen/perfc.h>
+#include <xen/spinlock.h>
+#include <xen/time.h>
+
 #include <public/sysctl.h>
 
 #define PERFCOUNTER( var, name )              { name, TYPE_SINGLE, 0 },

xen/include/xen/perfc.h

@@ -3,8 +3,7 @@
 
 #ifdef CONFIG_PERF_COUNTERS
 
-#include <xen/lib.h>
-#include <xen/smp.h>
+#include <xen/macros.h>
 #include <xen/percpu.h>
 
 /*