ARM: OMAP2+: control: determine control module base address from DT

There is no need to provide the control module base address through a
low-level API from the low-level IO init, as this information is
available through DT. This patch adds a new API to initialize the
control module though, but mostly makes the old API obsolete. The
old API can be completely removed once OMAP3 is made DT only.

Signed-off-by: Tero Kristo <t-kristo@ti.com>