tests/amdgpu: add bo eviction test

for(( i=1; i < 100; i++))
do
     echo "Hello, Welcome $i times "
     sudo ./amdgpu_test -s 1 -t 5
done

with above stricpt, run in two terminals, will reproduce Felix's swap leeking issue.

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>