mb/siemens/mc_ehl1: Enable pi608gp I2C driver

Add devicetree and Kconfig entries to enable additional configuration
of the Pericom PI7C9X2G608GP PCIe switch on this board variant.

The amplitude is being adjusted to 425 mV and de-emphasis level to
6.0 mV.

BUG=none
TEST=Read out the PCIe config space values of the switch and check if
they match with the ones configured over SMBus.

Change-Id: I11459f0794278ad614aa6e16c56df1ad578fe2f8
Signed-off-by: Jan Samek <jan.samek@siemens.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74434
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>

0 files changed, 0 insertions, 0 deletions