Refactoring of Cortex_M.Cache.
Refactoring of Cortex_M.Cache.

This now uses generics for cache-by-addr operations.

ellamosi/Ada_BMP_Library,lambourg/Ada_Drivers_Library,AdaCore/Ada_Drivers_Library,simonjwright/Ada_Drivers_Library,Fabien-Chouteau/Ada_Drivers_Library,AdaCore/Ada_Drivers_Library,Fabien-Chouteau/Ada_Drivers_Library,simonjwright/Ada_Drivers_Library