scmi_clock: clean up policy functions and return the SCMI agent's state instead of the physical state

Created by: mohamedasaker-arm

This patchset:

• cleans up the policy functions from the scmi_clock module. As seen in c49f043, due to the code complexity of the function can potentially introduce defects that can be difficult to spot and maintain. Refactoring mod_scmi_clock_config_set_policy function also helps to reduce the number of function calls and processing time, which can improve performance and efficiency. Furthermore, this commit refactors the module by removing all unnecessary parameters in helper functions. In addition, removing the FWK_WEAK to enforce the current policy until further requirements.
• Return the SCMI agent's state instead of the physical state. The current method of reading the clock state calls the Clock HAL directly, which can cause inconsistencies between what is being read by Clock Hal and what is being set in the SCMI agent state table. To address this, the existing scmi_clock_get_agent_clock_state helper function is used to read the clock state in relation to the requesting SCMI agent. i.e. function returns the state expected by SCMI agent.