platform/chrome: cros_ec_typec: Correct alt mode index

platform/chrome: cros_ec_typec: Correct alt mode index

[ Upstream commit 4e477663e396f48c5cfc5f2d75d4b514f409516a ]

Alt mode indices used by USB PD (Power Delivery) start with 1, not 0.

Update the alt mdoe registration code to factor this in to the alt mode
descriptor.

Fixes: de0f49487db3 ("platform/chrome: cros_ec_typec: Register partner altmodes")
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20220819190807.1275937-3-pmalani@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>