MdeModulePkg/BrotliCustomDecompressLib: Make brotli a submodule

Use submodule way to access brotli in MdeModulePkg based on
brotli version 666c3280cc11dc433c303d79a83d4ffbdd12cc8d.
The newly added BrotliDecUefiSupport.h/.c are used by directory
'brotli'.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2559

Cc: Liming Gao <liming.gao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

MdeModulePkg/Library/BrotliCustomDecompressLib/BrotliDecUefiSupport.h

@@ -0,0 +1,43 @@
+/** @file
+  BROTLI UEFI header file for definitions
+
+  Allows BROTLI code to build under UEFI (edk2) build environment
+
+  Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef __BROTLI_DECOMPRESS_UEFI_SUP_H__
+#define __BROTLI_DECOMPRESS_UEFI_SUP_H__
+
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#define memcpy                      CopyMem
+#define memmove                     CopyMem
+#define memset(dest,ch,count)       SetMem(dest,(UINTN)(count),(UINT8)(ch))
+#define malloc                      BrDummyMalloc
+#define free                        BrDummyFree
+
+typedef INT8     int8_t;
+typedef INT16    int16_t;
+typedef INT32    int32_t;
+typedef INT64    int64_t;
+typedef UINT8    uint8_t;
+typedef UINT16   uint16_t;
+typedef UINT32   uint32_t;
+typedef UINT64   uint64_t;
+typedef UINTN    size_t;
+
+VOID *
+BrDummyMalloc (
+  IN size_t   Size
+  );
+
+VOID
+BrDummyFree (
+  IN VOID *   Ptr
+  );
+
+#endif