ARM: dts: dra7: Remove ctrl_core and ctrl_general nodes

These nodes are wrongly placed. They must come under the
scm node. Nobody uses them either so get rid of them.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>