drm/amdgpu/gmc10.0: convert to IP version checking

Use IP versions rather than asic_type to differentiate
IP version specific features.

v2: squash in gmc fixes
v3: rebase

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