ARM: ARCH_MXC should select HAVE_CLK

All i.MX platforms support <linux/clk.h> calls and should select HAVE_CLK.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/Kconfig

@@ -454,6 +454,7 @@ config ARCH_MXC
 	select ARCH_MTD_XIP
 	select GENERIC_GPIO
 	select ARCH_REQUIRE_GPIOLIB
+	select HAVE_CLK
 	help
 	  Support for Freescale MXC/iMX-based family of processors