drm/amdgpu: fix the issue of reserving bad pages failed

In amdgpu_ras_reset_gpu, because bad pages may not be freed,
it has high probability to reserve bad pages failed.

Change to reserve bad pages when freeing VRAM.

v2:
1. avoid allocating the drm_mm node outside of amdgpu_vram_mgr.c
2. move bad page reserving into amdgpu_ras_add_bad_pages, if vram mgr
   reserve bad page failed, it will put it into pending list, otherwise
   put it into processed list;
3. remove amdgpu_ras_release_bad_pages, because retired page's info has
   been moved into amdgpu_vram_mgr

v3:
1. formate code style;
2. rename amdgpu_vram_reserve_scope as amdgpu_vram_reservation;
3. rename scope_pending as reservations_pending;
4. rename scope_processed as reserved_pages;
5. change to iterate over all the pending ones and try to insert them
   with drm_mm_reserve_node();

v4:
1. rename amdgpu_vram_mgr_reserve_scope as
amdgpu_vram_mgr_reserve_range;
2. remove unused include "amdgpu_ras.h";
3. rename amdgpu_vram_mgr_check_and_reserve as
amdgpu_vram_mgr_do_reserve;
4. refine amdgpu_vram_mgr_reserve_range to call
amdgpu_vram_mgr_do_reserve.

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Hawking Zhang <hawking.zhang@amd.com>
Signed-off-by: Dennis Li <Dennis.Li@amd.com>
Signed-off-by: Wenhui Sheng <Wenhui.Sheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>