Hardware initializes a single value in ttmp9 which is either the
workgroup ID X or cluster ID X. Most of this patch is a refactoring to
use a single `PreloadedValue` enumerator for this value, instead of two
enumerators `WORKGROUP_ID_X` and `CLUSTER_ID_X` referring to the same
value.
This makes it simpler to have a single attribute
`amdgpu-no-workgroup-id-x` indicating that this value is not used, which
in turns sets the TGID_EN_X bit appropriately to tell the hardware
whether to initialize it.
All of the above applies to Y and Z similarly.
Fixes: LWPSCGFX13-568
Co-authored-by: Jay Foad <jay.foad@amd.com>