vTPM: reformat event log to be byte-aligned

The event log generated by OpenFirmware in PowerPC is 4-byte aligned.
This patch reformats the log to be byte-aligned for the Linux client.

Signed-off-by: Hon Ching(Vicky) Lo <honclo@linux.vnet.ibm.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>