x86, uv: fix compile error in uv_hub.h

Impact: include file dependency cleanup

Fix compile errors of files that include asm/uv/uv_hub.h but do
not include linux/timer.h.

[ such files are not mainline right now. ]
Signed-of-by: NMike Travis <travis@sgi.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/include/asm/uv/uv_hub.h

@@ -13,6 +13,7 @@
 
 #include <linux/numa.h>
 #include <linux/percpu.h>
+#include <linux/timer.h>
 #include <asm/types.h>
 #include <asm/percpu.h>