CryptoPkg: Declare PcdEcEnabled in Library consuming OpensslLib

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3679
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3828

Tls/Base/Pei/Smm/RuntimeCryptLib.inf will use OpensslLib,
and the opensslconf.h in openssllib will use PcdEcEnabled,
but it is not declared in the inf file now,
it will cause warnings in some compilers.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Signed-off-by: Yi Li <yi1.li@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

CryptoPkg/Library/TlsLib/TlsLib.inf

@@ -41,6 +41,9 @@
   OpensslLib
   SafeIntLib
 
+[FixedPcd]
+  gEfiCryptoPkgTokenSpaceGuid.PcdEcEnabled
+
 [BuildOptions]
   #
   # suppress the following warnings so we do not break the build with warnings-as-errors: