microblaze: Use generic time config

Signed-off-by: Anna-Maria Gleixner <anna-maria@glx-um.de>
Cc: Michal Simek <monstr@monstr.eu>
Link: http://lkml.kernel.org/r/20120518163105.939597527@glx-um.de


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>