CryptoPkg/CrtLibSupport: add off_t

Add typedef for off_t.
Will be needed by openssl 3.0.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>

CryptoPkg/Library/Include/CrtLibSupport.h

@@ -104,6 +104,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 // Basic types mapping
 //
 typedef UINTN   size_t;
+typedef UINTN   off_t;
 typedef UINTN   u_int;
 typedef INTN    ptrdiff_t;
 typedef INTN    ssize_t;