fix(tpm): TPM_HASH_START address
fix(tpm): TPM_HASH_START address

Related Issue: https://github.com/lowRISC/opentitan/issues/15133

The TPM spec mentioned `TPM_HASH_START` should be return in one wait
state or less. TPM IP processes the request in HW to meet the
requirement.

However, TPM spec describes the HASH_START address as **0x20** in one
part and **0x28** in other parts (register table). The typo has existed
from early verion till now (v1.05).

This commit changes the address to **0x28** following the register
table. However, the register table also seems to have another typo,
which describes the `TPM_HASH_START` register size as two DWORDs (0x28
to 0x2F) not one DWORD (0x28 to 0x2B).

Signed-off-by: Eli Kim <3ca62a2ad87376be2697209a1770e1afdbbba220@opentitan.org>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan