tpm2_akparse man page: remove format details from description
tpm2_akparse man page: remove format details from description

According to PR #426 comment it's supposed to be opaque.

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