CryptoPkg/BaseCryptLib: make mVirtualAddressChangeEvent STATIC

CryptoPkg/BaseCryptLib: make mVirtualAddressChangeEvent STATIC

Make mVirtualAddressChangeEvent STATIC to prevent it from conflicting
with other variables of the same name that may be defined in other
libraries (e.g., MdeModulePkg/Universal/Variable/RuntimeDxe)
This also removes the risk of mVirtualAddressChangeEvent being merged with
other uninitialized variables with external linkage by toolchains that perform
COMMON allocation.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Qin Long <qin.long@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19146 6f19259b-4bc3-4df7-8a09-765794883524