tpm: Fix display of data in pubek sysfs entry

This patch fixes the TPM's pubek sysfs entry that is accessible as long
as the TPM doesn't have an owner. It was necessary to shift the access to the
data by -10 -- the first byte immediately follows the 10 byte header. The
line

 	data = tpm_cmd.params.readpubek_out_buffer;

sets it at the offset '10' in the packet, so we can read the data array
starting at offset '0'.

Before:

Algorithm: 00 0C 00 00
Encscheme: 08 00
Sigscheme: 00 00
Parameters: 00 00 00 00 01 00 AC E2 5E 3C A0 78
Modulus length: -563306801
Modulus:
28 21 08 0F 82 CD F2 B1 E7 49 F7 74 70 BE 59 8C
43 78 B1 24 EA 52 E2 FE 52 5C 3A 12 3B DC 61 71
[...]

After:

Algorithm: 00 00 00 01
Encscheme: 00 03
Sigscheme: 00 01
Parameters: 00 00 08 00 00 00 00 02 00 00 00 00
Modulus length: 256
Modulus:
AC E2 5E 3C A0 78 DE 6C 9E CF 28 21 08 0F 82 CD
F2 B1 E7 49 F7 74 70 BE 59 8C 43 78 B1 24 EA 52
[...]

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>