stm32/pin_defs_stm32: Fix pin printing to show IN mode correctly.

Prior to this commit, if you configure a pin as an output type (I2C in this
example) and then later configure it back as an input, then it will report
the type incorrectly.  Example:

    >>> import machine
    >>> b6 = machine.Pin('B6')
    >>> b6
    Pin(Pin.cpu.B6, mode=Pin.IN)
    >>> machine.I2C(1)
    I2C(1, scl=B6, sda=B7, freq=420000)
    >>> b6
    Pin(Pin.cpu.B6, mode=Pin.ALT_OPEN_DRAIN, pull=Pin.PULL_UP, af=Pin.AF4_I2C1)
    >>> b6.init(machine.Pin.IN)
    >>> b6
    Pin(Pin.cpu.B6, mode=Pin.ALT_OPEN_DRAIN, af=Pin.AF4_I2C1)

With this commit the last print now works:

    >>> b6
    Pin(Pin.cpu.B6, mode=Pin.IN)

0 files changed, 0 insertions, 0 deletions