Change in coreboot[master]: drivers/i2c/tpm/cr50: Add support to get and set BOARD_CFG register

[Nick Vaccaro (Code Review)]

Attention is currently required from: Subrata Banik, Tim Wawrzynczak, Christian Walter.
Nick Vaccaro has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/61721 )

Change subject: drivers/i2c/tpm/cr50: Add support to get and set BOARD_CFG register
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Patch Set 3:

(3 comments)

File src/drivers/i2c/tpm/cr50.c:

https://review.coreboot.org/c/coreboot/+/61721/comment/171d3202_95a1eb5a 
PS3, Line 535: 0.5.5 / 0.6.5
Why are there two versions?

https://review.coreboot.org/c/coreboot/+/61721/comment/611e02f5_34644796 
PS3, Line 547: cr50_get_board_cfg
Maybe name this "cr50_get_board_cfg_features()" to avoid confusion like occurred on line 574 since this does not return the entire board_cfg value?

https://review.coreboot.org/c/coreboot/+/61721/comment/6ed3f1cd_94db45e2 
PS3, Line 574: 	if (board_cfg_value & CR50_BOARD_CFG_LOCKBIT_MASK) {
This isn't going to work because cr50_get_board_cfg() strips off that bit prior to returning board config.