Fixes for grove and i2c changes (#31)

Apps/M5UnitTest/main/Source/GroveLookup.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <tactility/device.h>
+#include <tactility/drivers/grove.h>
+
+// Finds the I2C controller device exposed by the first grove port currently
+// in GROVE_MODE_I2C, by checking each grove port's child device type
+// (not by name - grove port names are not guaranteed, e.g. "port_a").
+Device* findGroveI2cDevice();
+
+// Same as findGroveI2cDevice() but for UART mode.
+Device* findGroveUartDevice();