amdgpu: add handle table implementation v2

The kernel handles are dense and the kernel always tries to use the
lowest free id. Use this to implement a more efficient handle table
by using a resizeable array instead of a hash.

v2: add handle_table_fini function, extra key checks,
    fix typo in function name

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-and-Tested-by: Junwei Zhang <Jerry.Zhang@amd.com>