drm/amdgpu: add drm buddy support to amdgpu

drm/amdgpu: add drm buddy support to amdgpu

- Switch to drm buddy allocator
- Add resource cursor support for drm buddy

v2(Matthew Auld):
  - replace spinlock with mutex as we call kmem_cache_zalloc
    (..., GFP_KERNEL) in drm_buddy_alloc() function

  - lock drm_buddy_block_trim() function as it calls
    mark_free/mark_split are all globally visible

v3(Matthew Auld):
  - remove trim method error handling as we address the failure case
    at drm_buddy_block_trim() function

v4:
  - fix warnings reported by kernel test robot <lkp@intel.com>

v5:
  - fix merge conflict issue

v6:
  - fix warnings reported by kernel test robot <lkp@intel.com>

v7:
  - remove DRM_BUDDY_RANGE_ALLOCATION flag usage

v8:
  - keep DRM_BUDDY_RANGE_ALLOCATION flag usage
  - resolve conflicts created by drm/amdgpu: remove VRAM accounting v2

v9(Christian):
  - merged the below patch
     - drm/amdgpu: move vram inline functions into a header
  - rename label name as fallback
  - move struct amdgpu_vram_mgr to amdgpu_vram_mgr.h
  - remove unnecessary flags from struct amdgpu_vram_reservation
  - rewrite block NULL check condition
  - change else style as per coding standard
  - rewrite the node max size
  - add a helper function to fetch the first entry from the list

v10(Christian):
   - rename amdgpu_get_node() function name as amdgpu_vram_mgr_first_block

v11:
   - if size is not aligned with min_page_size, enable is_contiguous flag,
     therefore, the size round up to the power of two and trimmed to the
     original size.
v12:
   - rename the function names having prefix as amdgpu_vram_mgr_*()
   - modify the round_up() logic conforming to contiguous flag enablement
     or if size is not aligned to min_block_size
   - modify the trim logic
   - rename node as block wherever applicable

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407224843.2416-1-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>