SourceLevelDebugPkg: Change use of EFI_D_* to DEBUG_*

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3739

Update all use of EFI_D_* defines in DEBUG() macros to DEBUG_* defines.

Cc: Andrew Fish <afish@apple.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael Kubacki <michael.kubacki@microsoft.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>

SourceLevelDebugPkg/Library/DebugAgent/DxeDebugAgent/SerialIo.c

@@ -368,7 +368,7 @@ InstallSerialIo (
                   NULL
                   );
   if (EFI_ERROR (Status)) {
-    DEBUG ((EFI_D_ERROR, "Debug Agent: Failed to install EFI Serial IO Protocol on Debug Port!\n"));
+    DEBUG ((DEBUG_ERROR, "Debug Agent: Failed to install EFI Serial IO Protocol on Debug Port!\n"));
   }
 }