tests/pyb: Update tests to run correctly on PYBv1.0.

In adcall.py the pyb module may not be imported, so use ADCAll directly.

In dac.py the DAC object now prints more info, so update .exp file.

In spi.py the SPI should be deinitialised upon exit, so the test can run a
second time correctly.

tests/pyb/adcall.py

@@ -5,19 +5,19 @@ pins = [Pin.cpu.A0, Pin.cpu.A1, Pin.cpu.A2, Pin.cpu.A3]
 # set pins to IN mode, init ADCAll, then check pins are ANALOG
 for p in pins:
     p.init(p.IN)
-adc = pyb.ADCAll(12)
+adc = ADCAll(12)
 for p in pins:
     print(p)
 
 # set pins to IN mode, init ADCAll with mask, then check some pins are ANALOG
 for p in pins:
     p.init(p.IN)
-adc = pyb.ADCAll(12, 0x70003)
+adc = ADCAll(12, 0x70003)
 for p in pins:
     print(p)
 
 # init all pins to ANALOG
-adc = pyb.ADCAll(12)
+adc = ADCAll(12)
 print(adc)
 
 # read all channels

tests/pyb/dac.py.exp

@@ -1 +1 @@
-<DAC>
+DAC(1, bits=8)

tests/pyb/spi.py

@@ -29,3 +29,5 @@ spi.init(SPI.MASTER)
 spi.send(1, timeout=100)
 print(spi.recv(1, timeout=100))
 print(spi.send_recv(1, timeout=100))
+
+spi.deinit()