drm/sched: Rename to drm_sched_wakeup_if_can_queue()

Rename drm_sched_wakeup() to drm_sched_wakeup_if_canqueue() since the former
is misleading, as it wakes up the GPU scheduler _only if_ more jobs can be
queued to the underlying hardware.

This distinction is important to make, since the wake conditional in the GPU
scheduler thread wakes up when other conditions are also true, e.g. when there
are jobs to be cleaned. For instance, a user might want to wake up the
scheduler only because there are more jobs to clean, but whether we can queue
more jobs is irrelevant.

v2: Separate "canqueue" to "can_queue". (Alex D.)

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://lore.kernel.org/r/20230517233550.377847-2-luben.tuikov@amd.com
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>