ARM: integrator: Add some Kconfig selections

The CMA and DMA_CMA Kconfig options need to be selected
by the Integrator in order to produce boot console on some
Integrator systems.

The REGULATOR and REGULATOR_FIXED_VOLTAGE need to be
selected in order to boot the system from an external
MMC card when using MMCI/PL181 from the device tree
probe path.

Select these things directly from the Kconfig so we are
sure to be able to bring the systems up with console
from any device tree.

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