soc/amd/common/include/spi: fix SPI_FIFO_LAST_BYTE define
The last byte of the SPI FIFO SPI_FIFO_LAST_BYTE is at offset 0xc6 of
the SPI controller's MMIO region for Stoneyridge and Picasso. Both
SPI_FIFO_LAST_BYTE and SPI_FIFO_DEPTH had an off-by-one error that ended
up cancelling out each other, so the resulting value for SPI_FIFO_DEPTH
isn't changed.
TEST=Timeless build results in identical image for Mandolin.
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I1676be902ccf57e2e9f69d81251b4315866a0628
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60116
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>