drm/amdgpu/gfx: assign the actual me0 queues per pipe

Set the actual number of queues per pipe for ME0 (gfx).
This way we will dump all of the queues properly in
dev core dumps.

Reviewed-by: Sunil Khatri <sunil.khatri@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>