tests/pyb: Make i2c and pyb1 pyboard tests run again.

For i2c.py: the accelerometer now uses the new I2C driver so need to
explicitly init the legacy i2c object to get the test working.

For pyb1.py: the legacy pyb.hid() call will crash if the USB_HID object is
not initialised.

tests/pyb/i2c.py

@@ -19,7 +19,8 @@ i2c.deinit()
 
 accel_addr = 76
 
-pyb.Accel() # this will init the bus for us
+pyb.Accel() # this will init the MMA for us
+i2c.init(I2C.MASTER, baudrate=400000)
 
 print(i2c.scan())
 print(i2c.is_ready(accel_addr))

tests/pyb/pyb1.py

@@ -29,8 +29,6 @@ pyb.enable_irq()
 
 print(pyb.have_cdc())
 
-pyb.hid((0, 0, 0, 0)) # won't do anything
-
 pyb.sync()
 
 print(len(pyb.unique_id()))