[NFC][Lanai][Hexagon] Define DEBUG_TYPE after including Debug.h. (#125440)

This patch fixes some warnings/errors that occur with certain
compilers-- due to existing code not following the idiom mentioned in
`Debug.h`:

```
// LLVM_DEBUG() requires the DEBUG_TYPE macro to be defined. Set it to "foo"
// specify that your debug code belongs to class "foo". **Be careful that you only
// do this after including Debug.h and not around any #include of headers.**
```

Author: nvjle

llvm/lib/Target/Hexagon/HexagonLoopAlign.cpp

@@ -9,13 +9,13 @@
 // number of instructions, set the prefLoopAlignment to 32 bytes (5).
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "hexagon-loop-align"
-
 #include "HexagonTargetMachine.h"
 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
 #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
 #include "llvm/Support/Debug.h"
 
+#define DEBUG_TYPE "hexagon-loop-align"
+
 using namespace llvm;
 
 static cl::opt<bool>

llvm/lib/Target/Lanai/Disassembler/LanaiDisassembler.cpp

@@ -20,8 +20,11 @@
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/TargetRegistry.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
 
+#define DEBUG_TYPE "lanai-disassembler"
+
 using namespace llvm;
 
 typedef MCDisassembler::DecodeStatus DecodeStatus;

llvm/lib/Target/Lanai/Disassembler/LanaiDisassembler.h

@@ -15,8 +15,6 @@
 
 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
 
-#define DEBUG_TYPE "lanai-disassembler"
-
 namespace llvm {
 
 class LanaiDisassembler : public MCDisassembler {