ARM: OMAP4+: control: add support for initializing control module via DT

OMAP4, OMAP5 and DRA7 now parse DT entries for control module address spaces,
and set up syscon mappings appropriately. Low level IO init is updated to
remove the legacy control module mappings for these devices also.

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