These functions are generally 1 machine instruction, and are used in
critical code, so makes sense to have them inline.
Also leave these functions uninverted (ie 0 means enable, 1 means
disable) and provide macro constants if you really need to distinguish
the states. This makes for smaller code as well (combined with
inlining).
Applied to teensy port as well.
Converts generted pins to use qstrs instead of string pointers.
This patch also adds the following functions:
pyb.Pin.names()
pyb.Pin.af_list()
pyb.Pin.gpio()
dir(pyb.Pin.board) and dir(pyb.Pin.cpu) also produce useful results.
pyb.Pin now takes kw args.
pyb.Pin.__str__ now prints more useful information about the pin
configuration.
I found the following functions in my boot.py to be useful:
```python
def pins():
for pin_name in dir(pyb.Pin.board):
pin = pyb.Pin(pin_name)
print('{:10s} {:s}'.format(pin_name, str(pin)))
def af():
for pin_name in dir(pyb.Pin.board):
pin = pyb.Pin(pin_name)
print('{:10s} {:s}'.format(pin_name, str(pin.af_list())))
```