ST7789.Rotation is limited to 4 rotations

[AshbyGeek]

The constructor for this class accepts an arbitrary number of rotations, but the rotation(...) setter is limited to just four.

Should change st7789.c line 1146 from:
mp_int_t rotation = mp_obj_get_int(value) % 4;
to:
mp_int_t rotation = mp_obj_get_int(value) % self->rotations_len;