i2c: stm32f7: use proper DMAENGINE API for termination
dmaengine_terminate_all() is deprecated in favor of explicitly saying if
it should be sync or async. Here, we use dmaengine_terminate_sync in
i2c_xfer and i2c_smbus_xfer handlers and rely on
dmaengine_terminate_async within interrupt handlers
(transmission error cases).
dmaengine_synchronize is added within i2c_xfer and i2c_smbus_xfer handler
to finalize terminate started in interrupt handlers.