crypto: vmx - Fix build error

When I refactored this Makefile, I accidentally changed the CONFIG
option.

Fixes: b52455a7 ("crypto: vmx - Align the short log with Makefile cleanups")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>