Move hos.* modules to hulk.*

src/hello/hello.d

@@ -9,8 +9,8 @@ import hello.scratch;
 import hulk.bootinfo;
 import hulk.header;
 import hulk.pagetable;
-import hos.cpu;
-import hos.memory;
+import hulk.cpu;
+import hulk.memory;
 import ldc.llvmasm;
 
 __gshared EFI_SYSTEM_TABLE * st;