test: undo change of platform auth in clear.sh after test is done
test: undo change of platform auth in clear.sh after test is done

The new test `clear.sh` introduced in 8821cff6 changes the platform auth
but does not change it back after it is done. If possible, tests should
always clean up after themselves. Hence, a call of tpm2_changeauth is
added.

Signed-off-by: joholl <45a711f7113e27c7d3924435698a26248acdf0b5@infineon.com>

01org/tpm2.0-tools,01org/tpm2.0-tools,01org/tpm2.0-tools