IntelFsp2Pkg: FspSecCore support for X64

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3893
1.Added FspSecCore support for X64.
2.Bumped FSP header revision to 7 to indicate FSP 64bit is supported.
3.Corrected few typos.

Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Cc: Ashraf Ali S <ashraf.ali.s@intel.com>
Signed-off-by: Ted Kuo <ted.kuo@intel.com>
Reviewed-by: Chasel Chiu <chasel.chiu@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>

IntelFsp2Pkg/FspSecCore/X64/ReadRsp.nasm

@@ -0,0 +1,22 @@
+;; @file
+;  Provide read RSP function
+;
+; Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;;
+;------------------------------------------------------------------------------
+
+    SECTION .text
+
+;------------------------------------------------------------------------------
+; UINTN
+; EFIAPI
+; AsmReadStackPointer (
+;   VOID
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmReadStackPointer)
+ASM_PFX(AsmReadStackPointer):
+    mov     rax, rsp
+    ret
+