Add clkctrl nodes for AM43xx SoC. These are going to be acting as
replacement for part of the existing clock data and the existing
clkctrl hooks under hwmod data.

This patch also removes any obsolete clock nodes, and reroutes all users
for these to use the new clkctrl clocks instead.

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