drm/amdkfd: make needs_pcie_atomics FW-version dependent

On some GPUs the PCIe atomic requirement for KFD depends on the MEC
firmware version. Add a firmware version check for this. The minimum
firmware version that works without atomics can be updated in the
device_info structure for each GPU type.

Move PCIe atomic detection from kgd2kfd_probe into kgd2kfd_device_init
because the MEC firmware is not loaded yet at the probe stage.

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>