[ARM] MX27 Clock rework

This changes MX27 to use common clkdev. It also cleans up MX27 clock
support to be more readable.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/plat-mxc/Kconfig b/arch/arm/plat-mxc/Kconfig
index 9cc2b16..10f65bf 100644
--- a/arch/arm/plat-mxc/Kconfig
+++ b/arch/arm/plat-mxc/Kconfig
@@ -15,6 +15,7 @@
 config ARCH_MX2
 	bool "MX2-based"
 	select CPU_ARM926T
+	select COMMON_CLKDEV
 	help
 	  This enables support for systems based on the Freescale i.MX2 family