anv: fix scratch buffer reloc in 3DSTATE_HS

anv: fix scratch buffer reloc in 3DSTATE_HS

We need to have the scratch buffer added to the pipeline BO tracking
list, so it's added to the batch buffer and finally to the execbuffer
list. Otherwise we pagefault (or read the default scratch page on
i915).

Fixes
dEQP-VK.subgroups.ballot_broadcast.graphics.subgroupbroadcast_u16vec4
on CI (and probably other tests).

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: 2028f1caa385 ("anv: emit 3DSTATE_HS in cmd_buffer_flush_gfx_state")
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21653>