[Bug]: ControlNet is run on every step for area composition

Based on the [workflow](https://comfyanonymous.github.io/ComfyUI_examples/area_composition/square_area_for_2_subjects.png) from the examples, if you put a ControlNet there (e.g. tile), a resize and broadcast will occur on every step since `x_noisy` will always have a different width and height from the previous `cond_hint` due to being one of the areas. This doesn't occur in a workflow without area composition, i.e `cond_hint` gets calculated only once because there's only 1 noise to worry about.

`get_control()`:
https://github.com/comfyanonymous/ComfyUI/blob/432ba1c1793e5f9bf6a1ec877768d3cf6859a1ae/comfy/controlnet.py#L162-L168