i.MXC family: Adding timer support

This patch adds timer support for the i.MX machine family. This code can
be used on the following machs:

 - i.MX1 (tested)
 - i.MX2 (i.MX21 (to be tested), i.MX27 (tested))
 - i.MX3 (i.MX31 (tested))

TODO: It seems impossible to build a kernel for more than one CPU because the
timer do not follow the platform device rules. So it does only work if
timer 1 can be accessed on all CPUs at the same address.

Signed-off-by: Juergen Beisert <j.beisert@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5c8c1a8..8a9a84c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -367,6 +367,8 @@
 
 config ARCH_MXC
 	bool "Freescale MXC/iMX-based"
+	select GENERIC_TIME
+	select GENERIC_CLOCKEVENTS
 	select ARCH_MTD_XIP
 	select GENERIC_GPIO
 	select HAVE_GPIO_LIB