vendorcode/intel/fsp/fsp2_0/cpx_sp: Set correct stack number for IOU3
PSTACK2 (IOU3) should be stack number 4, mainboard uses stack number as
the index to access the bus number array read by get_stack_busnos().
Without the fix it would get the wrong bus number (0xb1).
Tested=On OCP Delta Lake, dmidecode -t 9 to verify slots bus number on
IOU3 are correct (0xb2).
Change-Id: I1c9e49bbc9a00de82d1fc67b3b4ed47e03eacdda
Signed-off-by: Johnny Lin <johnny_lin@wiwynn.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45022
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jonathan Zhang <jonzhang@fb.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>