Cleanup Null Stack Cookie Implementation

edk2 PR https://github.com/tianocore/edk2/pull/6433

 cleans up the
null stack cookie implementation, no longer requiring DSCs to
manually add the null stack cookie lib to Sec modules.

This commit changes all DSCs in edk2-platforms to drop the manual
adding.

Signed-off-by: Oliver Smith-Denny <osde@linux.microsoft.com>