core: Add missing override specifiers where applicable

Applies the override specifier where applicable. In the case of
destructors that are  defaulted in their definition, they can
simply be removed.

This also removes the unnecessary inclusions being done in audin_u and
audrec_u, given their close proximity.

src/core/arm/unicorn/arm_unicorn.h

@@ -18,7 +18,7 @@ namespace Core {
 class ARM_Unicorn final : public ARM_Interface {
 public:
     explicit ARM_Unicorn(Timing::CoreTiming& core_timing);
-    ~ARM_Unicorn();
+    ~ARM_Unicorn() override;
 
     void MapBackingMemory(VAddr address, std::size_t size, u8* memory,
                           Kernel::VMAPermission perms) override;