drm/amdgpu/pm/amdgpu_smu: convert more IP version checking

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

v2: switch if statement to a switch statement

Acked-by: Christian König <christian.koenig@amd.com> (v1)
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>