ARM: DRA7: Select missing options for SoC only build

DRA7 does use OPP, uses OMAP interconnect and also does require SCU.
These are missing in the SoC only build of DRA7 breaking various PM
features in DRA7 only build.

Reported-by: Carlos Hernandez <ceh@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>