soc/intel/cannonlake: Fix return values for get_param_value

Commit 41483c9 (soc/intel/cannonlake: Add required FSP UPD changes for
CML) changed the enum values for PCH_SERIAL_IO_MODE so that 0 is
invalid and valid values start from 1. However, get_param_value was
not updated to correctly subtract 1 before returning any value. This
change adds a macro PCH_SERIAL_IO_INDEX to apply the subtract 1
operation on any value that get_param_value needs to return.

BUG=b:128946016
TEST=Verified that hatch boots successfully.

Change-Id: I4e32fcd1efe4a535251f0ec58662a2dc5f70e8b0
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31974
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-by: Maulik V Vaghela <maulik.v.vaghela@intel.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

0 files changed, 0 insertions, 0 deletions