kernel/process: Report total physical memory used to svcGetInfo

Reports the (mostly) correct size through svcGetInfo now for queries to
total used physical memory. This still doesn't correctly handle memory
allocated via svcMapPhysicalMemory, however, we don't currently handle
that case anyways.

src/core/hle/kernel/process.cpp

@@ -76,6 +76,10 @@ SharedPtr<ResourceLimit> Process::GetResourceLimit() const {
     return resource_limit;
 }
 
+u64 Process::GetTotalPhysicalMemoryUsed() const {
+    return vm_manager.GetCurrentHeapSize() + main_thread_stack_size + code_memory_size;
+}
+
 ResultCode Process::ClearSignalState() {
     if (status == ProcessStatus::Exited) {
         LOG_ERROR(Kernel, "called on a terminated process instance.");