drm/radeon: add WQ_PERCPU to alloc_workqueue users

drm/radeon: add WQ_PERCPU to alloc_workqueue users

This continues the effort to refactor workqueue APIs, which began with
the introduction of new workqueues and a new alloc_workqueue flag in:

   commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq")
   commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag")

The refactoring is going to alter the default behavior of
alloc_workqueue() to be unbound by default.

With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND),
any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND
must now use WQ_PERCPU. For more details see the Link tag below.

In order to keep alloc_workqueue() behavior identical, explicitly request
WQ_PERCPU.

Suggested-by: Tejun Heo <tj@kernel.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>