drm/amdgpu: convert amdgpu_amdkfd_gpuvm.c to IP version checks

For consistency with the rest of the code.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>