soc: move SoC driver for the ARM Integrator

This creates a new SoC bus driver for the ARM Integrator
family core modules to register the SoC bus and provide
sysfs info for the core module. We delete the corresponding
code from the Integrator machine and select this driver to
get a clean result.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>