drm/amdgpu/gfx10: new approach to load gfx10 me fw (v4)

gfx10 allows to only upload me jumptable while save the whole
me image at gtt memory.

v2: program CP_ME_IC_BASE_CNTL to default value
v3: switch to use amdgpu_bo_create_reserved to create me fw bo
v4: split common code from gfx10 code

Signed-off-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>