module/scmi_power_capping: allow multi fast channels access

In the original implementation every SCMI power capping domain was allowed only a set of 4 fast channels corresponding to the messages CAP_GET, CAP_SET, PAI_GET and PAI_SET which meant each domain can be accessed by only one agent for a specific fast channel message.

In the new implementation, fast channels are decoupled from the SCMI power capping domains. Each fast channel can be configured to connect to an agent, an SCMI power capping domain and an SCMI power capping message, this allows several agents to access the same SCMI power capping domain via fast channels.

Signed-off-by: Ahmed Gadallah ahmed.gadallah@arm.com