soc/amd/stoneyridge: Add API to initialize non-early_init i2c buses

Provide a method for initializing i2c buses that are not marked as
early_init in the device tree.  These i2c buses can be enabled in a
mainboard's ramstage, for example.

BUG=b:69407112
TEST=Boot depthcharge w/ CLI enabled on grunt.
  devbeep
  => plays beep
BRANCH=None

Change-Id: I6e49b0de9116138ba102377d283e22d7b50d7dca
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-on: https://review.coreboot.org/23553
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
2 files changed