selftests: tpm2: test_smoke: Run only when TPM2 is avaialable.

Since Linux 5.6 tpm_version_major sysfs file is avaialble which gives
the TPM version.

Using this file the test can be skipped on systems with TPM 1.2.
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

tools/testing/selftests/tpm2/test_smoke.sh

@@ -5,5 +5,7 @@
 ksft_skip=4
 
 [ -e /dev/tpm0 ] || exit $ksft_skip
+read tpm_version < /sys/class/tpm/tpm0/tpm_version_major
+[ "$tpm_version" == 2 ] || exit $ksft_skip
 
 python3 -m unittest -v tpm2_tests.SmokeTest 2>&1