dt-bindings: document access-controllers property for coresight peripherals

dt-bindings: document access-controllers property for coresight peripherals

Document the access-controllers for coresight peripherals in case some
access checks need to be performed to use them.

Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260226-debug_bus-v6-1-5d794697798d@foss.st.com
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>