[TG3]: Add nvram lock-out support for 5752 TPM

Add support for the NVRAM lock-out feature for TPM in 5752. If lock-out
is enabled, certain NVRAM registers cannot be written to.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>