vtpm: passthru requests to manager

vtpm: passthru requests to manager

When sending commands to a vTPM, commands with the VTPM_TAG_REQ2 tag are
passed directly to the TPM Manager since they are used in the management
interface to the TPM Manager. The VTPM_TAG_REQ tag is translated to
TPM_TAG_RQU_COMMAND to allow access to the physical TPM for certain
ordinals (PCRRead, Extend, and GetRandom).

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Ian Campbell <ian.campbell@citrix.com>