sysutils/nvtop: New port: GPU & Accelerator process monitoring

NVTOP stands for Neat Videocard TOP, a (h)top like task monitor for GPUs
and accelerators. It can handle multiple GPUs and print information
about them in a htop-familiar way.

Currently supported vendors are AMD (Linux amdgpu driver), Apple
(limited M1 & M2 support), Huawei (Ascend), Intel (Linux i915/Xe
drivers), NVIDIA (Linux proprietary divers), Qualcomm Adreno (Linux MSM
driver), Broadcom VideoCore (Linux v3d driver), Rockchip, MetaX (MXSML
driver), Enflame (Linux EFML driver).

PR: 294825
Sponsored by: UNIS Labs