linux-phytec-ti

Documentation: bindings: update the berlin chip and system ctrl doc

Now that the rework to have one sub-node per device in the chip and
system controllers is done, their dedicated compatible can be removed.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>