Fix the bug that sometimes the channel cannot be aligned in FPN

[mjq2020]

In YOLOv5, v6, v8, PPYOLOE, when the widen_factor is certain, the number of convolution input channels cannot be aligned with the corresponding feature map #781

[CLAassistant]

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[hhaAndroid]

@mjq2020 Thank you very much for your PR, I will review it as soon as possible and give you feedback.