soc/amd/stoneyridge: Add function to enable I2C host controllers

In preparation for moving AGESA calls out of bootblock:
Add function to enable the four stoneyridge I2C engines.

BUG=b:65442212
BRANCH=master
TEST=abuild, build Gardenia, build and boot Grunt (with other changes
to call code not committed at this time)

Change-Id: Icb55c49cf56c65a9c2e1838cff1ed5afc04e1826
Signed-off-by: Garrett Kirkendall <garrett.kirkendall@amd.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/25026
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Richard Spiegel <richard.spiegel@silverbackltd.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2 files changed