tpm2_create: show usage when required options aren't specified
tpm2_create: show usage when required options aren't specified

If the user misses mandatory options or specifies incompatible options show
the usage information.

Signed-off-by: Joshua Lock <9750fc34162235efa862f2505c1a01f735e97af7@intel.com>

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