ARM: mxs: move timer driver into drivers/clocksource

Move mxs timer driver into drivers/clocksource as mxs_timer.c.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 4d8283a..89c5adc 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -16,6 +16,7 @@
 obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
 obj-$(CONFIG_ARMADA_370_XP_TIMER)	+= time-armada-370-xp.o
 obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835_timer.o
+obj-$(CONFIG_ARCH_MXS)		+= mxs_timer.o
 obj-$(CONFIG_SUNXI_TIMER)	+= sunxi_timer.o
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra20_timer.o
 obj-$(CONFIG_VT8500_TIMER)	+= vt8500_timer.o