More readable HLS arg name

[Kuree]

Introduced a guess_name function in HLS codegen so that instead of using arg_%d, it's now using more human readable naming used in Halide code. This is extremely helpful because user now can specify the DMA channel loading order in the driver code automatically, given the pipeline_zynq buffer preparing sequence. If the code fails to guess the argument name, it will fall back to arg_%d.

• We've rewrote hwacc driver code so that it reads information directly from device tree, instead of through parametrization (one driver to rule them all.)

[Kuree]

Fixed in a889989.

[Kuree]

Done.

[jingpu]

The build failure looks relative.

[Kuree]

It seems like static functions cannot have const qualifier. See: https://stackoverflow.com/a/19812883

I will revert it back to non-const function.