platform/chrome: cros_ec_typec: Init mutex in Thunderbolt registration

platform/chrome: cros_ec_typec: Init mutex in Thunderbolt registration

cros_typec_register_thunderbolt() missed initializing the `adata->lock`
mutex.  This leads to a NULL dereference when the mutex is later
acquired (e.g. in cros_typec_altmode_work()).

Initialize the mutex in cros_typec_register_thunderbolt() to fix the
issue.

Cc: stable@vger.kernel.org
Fixes: 3b00be26b16a ("platform/chrome: cros_ec_typec: Thunderbolt support")
Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Link: https://lore.kernel.org/r/20260505053403.3335740-1-tzungbi@kernel.org
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>