ARM: OMAP depends on MMU

There is no way to build OMAP kernels without an MMU
at this point because of dependencies on MMU-only functions.

As long as nobody is interested in fixing this, let's just disable
this platforms for nommu kernels.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/Kconfig

@@ -934,6 +934,7 @@ config ARCH_DAVINCI
 
 config ARCH_OMAP
 	bool "TI OMAP"
+	depends on MMU
 	select HAVE_CLK
 	select ARCH_REQUIRE_GPIOLIB
 	select ARCH_HAS_CPUFREQ