scmi_clock/test: invoke the message_handler directly
requested to merge github/fork/mohamedasaker-arm/moa/scmi_clock-test-invoce-message-handler-directly into master
Created by: mohamedasaker-arm
Instead of binding APIs invoke the message_handler directly. To remove unnecessary code and simplify the test.
Change-Id: Id440d4ca6d951877e78e74374f00877d78d8559c