Changes in this commit are:
- Use mphal_xx functions whenever possible.
- Remove obsolete includes.
- Clean up traces of a non-functional pin.irq() from earlier builds.
Pin.irq() will be added in further commits in a working manner.
Instead of being an explicit field, it's now a slot like all the other
methods.
This is a marginal code size improvement because most types have a make_new
(100/138 on PYBV11), however it improves consistency in how types are
declared, removing the special case for make_new.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>