ARM: OMAP3: cm-t3517: use GPTIMER for system clock

cm-t3517 starting from revision 1.2 does not have the 32K oscilator
wired to the AM3517 SoC.
Therefore switch to use the GPTIMER for system clock.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index bbe3cc2..b9cff72 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -594,6 +594,9 @@
 OMAP_SYS_32K_TIMER_INIT(3_secure, 12, OMAP3_32K_SOURCE, "ti,timer-secure",
 			2, OMAP3_MPU_SOURCE);
 OMAP_SYS_TIMER(3_secure, sync32k);
+OMAP_SYS_GP_TIMER_INIT(3_gp, 1, OMAP3_MPU_SOURCE, "ti,timer-alwon",
+		       2, OMAP3_MPU_SOURCE);
+OMAP_SYS_TIMER(3_gp, gptimer);
 #endif /* CONFIG_ARCH_OMAP3 */
 
 #ifdef CONFIG_SOC_AM33XX