dt-bindings: mfd: ti,j721e-system-controller: Remove syscon from example

The binding for ti,am654-ehrpwm-tbclk was updated to remove the syscon
compatible hint. Remove the same from the example in this binding.

Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20230623201519.194269-1-afd@ti.com


Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>