arm: Move tbl to arch_global_data

Move this field into arch_global_data and tidy up.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/pxa/timer.c b/arch/arm/cpu/pxa/timer.c
index a8f7462..7799c14 100644
--- a/arch/arm/cpu/pxa/timer.c
+++ b/arch/arm/cpu/pxa/timer.c
@@ -31,7 +31,7 @@
 
 #define	TIMER_LOAD_VAL	0xffffffff
 
-#define	timestamp	(gd->tbl)
+#define	timestamp	(gd->arch.tbl)
 #define	lastinc		(gd->lastinc)
 
 #if defined(CONFIG_CPU_PXA27X) || defined(CONFIG_CPU_MONAHANS)