arm: omap4: add common twl configurations for vdd1, vdd2 and vdd3

VDD1 is used for MPU voltage, VDD2 is for IVA and VDD3 is for CORE.
These are needed by DVFS. This patch also adds external controller
support for these regulators, the default I2C control channel can't
be used to modify the voltages for these regulators on TWL6030.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>