ARM: plat-nomadik: move MTU, kill plat-nomadik

This moves the MTU timer driver from arch/arm/plat-nomadik
to drivers/clocksource and moves the header file to the
platform_data directory.

As this moves the last file being compiled to an object out
of arch/arm/plat-nomadik, we have to "turn off the light"
and delete the plat-nomadik directory, because it is not
allowed to have an empty Makefile in a plat-* directory.
This is probably also a desired side effect of depopulating
the arch/arm directory of drivers. Luckily we have just
deleted all the <plat/*> include files prior to this so
by moving the last one we may delete the directory.

After this all the Ux500 and Nomadik device drivers live
outside of the arch/arm hierarchy.

Cc: Alessandro Rubini <rubini@unipv.it>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>