arm: Eliminate all TPM related code if CONFIG_TPM is not set

Peter Maydell <peter.maydell@linaro.org>

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210614191335.1968807-3-stefanb@linux.ibm.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>