arm_interface: Replace kernel vm_manager include with a forward declaration

Avoids an unnecessary inclusion and also uncovers three places where
indirect inclusions were relied upon, which allows us to also resolve
those.

src/core/arm/dynarmic/arm_dynarmic.cpp

@@ -15,6 +15,7 @@
 #include "core/gdbstub/gdbstub.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/svc.h"
+#include "core/hle/kernel/vm_manager.h"
 #include "core/memory.h"
 
 namespace Core {

src/core/arm/dynarmic/arm_dynarmic.h

@@ -12,6 +12,10 @@
 #include "core/arm/exclusive_monitor.h"
 #include "core/arm/unicorn/arm_unicorn.h"
 
+namespace Memory {
+struct PageTable;
+}
+
 namespace Core {
 
 class ARM_Dynarmic_Callbacks;