tests/amdgpu: refactoring and update amd_basic tests
1. Create auxiliary directory amdgpu into igt-gpu-tools/lib
Put all helpers and reusable functions into this directory using
the following assumptions:
- group memory alloc/free functions into separate file amd_memory.c and h.
- group command submissions helper functions for GFX, COMPUTE and SDMA into
separate file amd_command_submission.c and h.
- for compute put nop command submission into separate file amd_compute.c and h.
- for graphics put command submission into separate file amd_gfx.c and h.
- for fence put command submission into separate file amd_fence.c and h.
2. Simplify implementation and reduce the number of local variables and allocations.
3. The file igt-gpu-tools/tests/amdgpu/amd_basic.c has only functions responsible
for single sub test:
- amdgpu_memory_alloc
- amdgpu_userptr_test
- amdgpu_command_submission_gfx
- amdgpu_command_submission_compute
- amdgpu_command_submission_multi_fence
- amdgpu_command_submission_sdma
- amdgpu_semaphore_test
No helper functions into amd_basic.c file.