drm/amd/display: properly handle family setting for early GC 11.5.4

drm/amd/display: properly handle family setting for early GC 11.5.4

Early variants need an override.

Fixes: 57d00816c6a9 ("drm/amdgpu: set family for GC 11.5.4")
Cc: Pratik Vishwakarma <Pratik.Vishwakarma@amd.com>
Cc: Roman Li <Roman.Li@amd.com>
Cc: Mario Limonciello <superm1@kernel.org>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Tested-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>