[M] Change in coreboot[master]: security/tpm: make tis_probe() return tpm_family

[Krystian Hebel (Code Review)]

Attention is currently required from: Michał Żygowski, Christian Walter, Julius Werner, Sergii Dmytruk.

Krystian Hebel has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/69159 )

Change subject: security/tpm: make tis_probe() return tpm_family
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Patch Set 1:

(1 comment)

File src/drivers/i2c/tpm/tpm.c:

https://review.coreboot.org/c/coreboot/+/69159/comment/c4b64421_dd2a5640 
PS1, Line 461: 	*tpm_family = 1;
> Are you sure this is guaranteed? I thought I recall that 9645 can be 2. […]

TPM 2.0 for I2C does exist and it should be detected in the same way as for SPI/LPC. That being said, those tests aren't complete because they only test TIS version. Full check, regardless of bus, should be something like:

```
if (TPM_INTF_CAPABILITY.InterfaceVersion == 0)
    tpm_family = 1     // (TIS <= 1.21, not used by TPM 2.0 devices)
else                   // (TIS 1.3, used both by TPM 1.2 and 2.0)
    if (TPM_STS.tpmFamily == 0)
        tpm_family = 1
    else
        tpm_family = 2
```