soc/amd/common/psp: add and call PSP SMI SPI access function stubs

Add stub functions for the SPI flash access from the PSP SMI handler
and call them for the corresponding P2C mailbox commands.

Parts of this patch are taken from CB:65523.

Document #55758 Rev. 2.04 was used as a reference.

Test=When selecting SOC_AMD_COMMON_BLOCK_PSP_SMI, Mandolin still builds

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Signed-off-by: Ritul Guru <ritul.bits@gmail.com>
Change-Id: Iedbc9d41eb0d4e8d81eeba9c01281161eb839991
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83756
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions