x86/kvm/Kconfig: Ensure CRYPTO_DEV_CCP_DD state at minimum matches KVM_AMD

Prevent a config where KVM_AMD=y and CRYPTO_DEV_CCP_DD=m thereby ensuring
that AMD Secure Processor device driver will be built-in when KVM_AMD is
also built-in.

v1->v2:
* Removed usage of 'imply' Kconfig option.
* Change patch commit message.

Fixes: 505c9e94 ("KVM: x86: prefer "depends on" to "select" for SEV")

Cc: <stable@vger.kernel.org> # 4.16.x
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>