libs/kaptan-i2c: add non-blocking controller contract

libs/kaptan-stm32f7/Cargo.toml

@@ -16,6 +16,7 @@ stm32f722 = ["stm32f7/stm32f722"]
 [dependencies]
 cortex-m = "0.7"
 kaptan-dma = { path = "../kaptan-dma" }
+kaptan-i2c = { path = "../kaptan-i2c" }
 kaptan-spi = { path = "../kaptan-spi" }
 kaptan-time = { path = "../kaptan-time" }
 stm32f7 = { version = "0.16", default-features = false }