MX5: Reuse the gd->tbl value for timestamp and add gd->lastinc for lastinc bss

The usage of bss values in drivers before initialisation of bss is forbidden.
In that special case some data in .rel.dyn gets corrupted.

This patch is the same as recently applied for arm926js architecture.
Signed-off-by: NStefano Babic <sbabic@denx.de>
CC: Heiko Schocher <hs@denx.de>

arch/arm/cpu/armv7/mx5/timer.c

@@ -44,8 +44,10 @@ static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
 #define GPTCR_CLKSOURCE_32 (4<<6)	/* Clock source */
 #define GPTCR_TEN       (1)	/* Timer enable */
 
-static ulong timestamp;
-static ulong lastinc;
+DECLARE_GLOBAL_DATA_PTR;
+
+#define timestamp (gd->tbl)
+#define lastinc (gd->lastinc)
 
 int timer_init(void)
 {