ARM i.MX21: implement clocks using common clock framework

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index c03920a..d23cebd 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -43,6 +43,7 @@
 	bool
 	select MACH_MX21
 	select CPU_ARM926T
+	select COMMON_CLK
 	select IMX_HAVE_IOMUX_V1
 	select MXC_AVIC