Padding size calculation issue

[SUZhaoyu]

The calculation of padding size seems to be conflicted in the kernel registration and execution. In kernel registration, the padding size is calculated based on the effective kernel size (taking dilation into consideration), while in the execution part, it is calculated based on the real kernel size.

I don't know how much this will affect the performance, but the output result does change given different padding sizes when dilation is not 1 (has been tested).