mod/ppu_v1: Operarting Mode API
This patch introduces a new public API that will allow for operating mode management. This includes enabling or disabling the operating mode, the dynamic policy and amending the default values that will be applied.
It also includes unit test coverage.
Signed-off-by: Katherine Vincent katherine.vincent@arm.com (cherry picked from commit 146a32984bcdd77712f85fcb7733bd094ba8fee5)