Change in coreboot[master]: mb/google/volteer: Select board-specific options per board

[Angel Pons (Code Review)]

Attention is currently required from:  Felix Singer, Tim Wawrzynczak, Nick Vaccaro.
Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/60370 )

Change subject: mb/google/volteer: Select board-specific options per board
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Patch Set 3: Code-Review+1

(1 comment)

File src/mainboard/google/volteer/Kconfig:

https://review.coreboot.org/c/coreboot/+/60370/comment/46282456_43bac7c5 
PS3, Line 30: 	select MAINBOARD_HAS_CHROMEOS
I wonder if this would work:

select MAINBOARD_HAS_SPI_TPM_CR50 if !MAINBOARD_HAS_I2C_TPM_CR50

This would choose `MAINBOARD_HAS_SPI_TPM_CR50` by default unless `MAINBOARD_HAS_I2C_TPM_CR50` is selected.