dt-bindings: arm: Add label in the coresight components

Current name of coresight component's folder consists of prefix of
the device and the id in the device list. When run 'ls' command,
we can get the register address of the device. Take CTI for example,
if we want to set the config for modem CTI, but we can't know which
CTI is modem CTI from all current information.

cti_sys0 -> ../../../devices/platform/soc@0/138f0000.cti/cti_sys0
cti_sys1 -> ../../../devices/platform/soc@0/13900000.cti/cti_sys1

Add label to show hardware context information of each coresight
device. There will be a sysfs node label in each device folder.

cat /sys/bus/coresight/devices/cti_sys0/label

Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250816072529.3716968-2-quic_jinlmao@quicinc.com