firmware: octsimtest: mcp23017 initializaiton

* driver should not have hard-coded understanding about I/O directions
* board code should pass the I/O direction to driver
* board code should use the correct I/O directions (A0..7, B0: output)

Change-Id: Id4a8e012a33cee01bb489e612e17920760b9be59
diff --git a/firmware/libboard/octsimtest/include/mcp23017.h b/firmware/libboard/octsimtest/include/mcp23017.h
index 962a1d5..c0f4b13 100644
--- a/firmware/libboard/octsimtest/include/mcp23017.h
+++ b/firmware/libboard/octsimtest/include/mcp23017.h
@@ -18,7 +18,7 @@
 
 #define MCP23017_ADDRESS 0x20
 
-int mcp23017_init(uint8_t slave);
+int mcp23017_init(uint8_t slave, uint8_t iodira, uint8_t iodirb);
 int mcp23017_test(uint8_t slave);
 int mcp23017_toggle(uint8_t slave);
 //int mcp23017_write_byte(uint8_t slave, uint8_t addr, uint8_t byte);