drm/amdgpu: Copy MEC FW version to MEC2 if we skipped loading MEC2

If we skipped loading MEC2 firmware separately
from MEC, then MEC2 will be running the same
firmware image. Copy the MEC version and feature
numbers into MEC2 version and feature numbers.
This is needed for things like GWS support, where
we rely on knowing what version of firmware is
running on MEC2. Leaving these MEC2 entries blank
breaks our ability to version-check enables and
workarounds.

Signed-off-by: Joseph Greathouse <Joseph.Greathouse@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>