Change directory structure to align with Atmel softpack

This way we can easily check with 'diff' for differences in our code and
Atmel softpack.  Also, this layout is more suitable for building various
different firmware images (e.g. factory-test, dfu-loader, main
application) for a variety of different boards (simtrace, owhw, qmod).

firmware/libboard/qmod/include/i2c.h

@@ -0,0 +1,5 @@
+#pragma once
+
+void i2c_pin_init(void);
+int eeprom_write_byte(uint8_t slave, uint8_t addr, uint8_t byte);
+int eeprom_read_byte(uint8_t slave, uint8_t addr);