drm/amdgpu: Replace in_task() in gfx_v8_0_parse_sq_irq()

gfx_v8_0_parse_sq_irq() is using in_task() to distinguish if it is
invoked from a workqueue worker or directly from the interrupt handler.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by the
caller, which usually knows the context.

gfx_v8_0_parse_sq_irq() is invoked directly either from a worker or from
the interrupt service routine. The worker is only bypassed if the worker
is already busy.

Add an argument `from_wq' to gfx_v8_0_parse_sq_irq() which is true if
invoked from the worker.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>