coresight-tpda: Add support to configure CMB element

Read the CMB element size from the device tree. Set the register
bit that controls the CMB element size of the corresponding port.

Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/1707024641-22460-6-git-send-email-quic_taozha@quicinc.com