timer: Add MPC83xx timer driver

Add a timer driver for the MPC83xx architecture.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/timer/Makefile b/drivers/timer/Makefile
index ed482df..7f19c49 100644
--- a/drivers/timer/Makefile
+++ b/drivers/timer/Makefile
@@ -11,6 +11,7 @@
 obj-$(CONFIG_ATMEL_PIT_TIMER) += atmel_pit_timer.o
 obj-$(CONFIG_CADENCE_TTC_TIMER)	+= cadence-ttc.o
 obj-$(CONFIG_DESIGNWARE_APB_TIMER)	+= dw-apb-timer.o
+obj-$(CONFIG_MPC83XX_TIMER) += mpc83xx_timer.o
 obj-$(CONFIG_OMAP_TIMER)	+= omap-timer.o
 obj-$(CONFIG_ROCKCHIP_TIMER) += rockchip_timer.o
 obj-$(CONFIG_SANDBOX_TIMER)	+= sandbox_timer.o