[HIP][HIPIFY] Make hipMemcpyParam2D coherent with cuMemcpy2D

+ Makes hip_Memcpy2D struct compatible with CUDA_MEMCPY2D struct
+ Add hipMemcpyParam2D support in nvcc fallback path
+ Update hipify-clang, tests and docs accordingly

docs/markdown/CUDA_Driver_API_functions_supported_by_HIP.md

@@ -861,7 +861,7 @@
 | `cuMemAllocManaged`                                       |                               |
 | `cuMemAllocPitch`                                         |                               |
 | `cuMemcpy`                                                |                               |
-| `cuMemcpy2D`                                              |                               |
+| `cuMemcpy2D`                                              | `hipMemcpyParam2D`            |
 | `cuMemcpy2DAsync`                                         |                               |
 | `cuMemcpy2DUnaligned`                                     |                               |
 | `cuMemcpy3D`                                              |                               |