dmaengine: idxd: Remove the unused function set_completion_address()

dmaengine: idxd: Remove the unused function set_completion_address()

The function set_completion_address is defined in the dma.c file, but not
called elsewhere, so remove this unused function.

drivers/dma/idxd/dma.c:66:20: warning: unused function 'set_completion_address'.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3416
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20221212033514.5831-1-jiapeng.chong@linux.alibaba.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>