dmaengine: Replace zero-length array with flexible-array

Documentation/process/deprecated.rst suggests that zero-length
and one-element arrays are deprecated, flexible-array members
should be used instead.

Signed-off-by: Chelsy Ratnawat <chelsyratnawat2001@gmail.com>
Link: https://lore.kernel.org/r/20250830132633.1803300-1-chelsyratnawat2001@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: ChelsyRatnawat

drivers/dma/imx-sdma.c

@@ -256,7 +256,7 @@ struct sdma_script_start_addrs {
 	/* End of v3 array */
 	union { s32 v3_end; s32 mcu_2_zqspi_addr; };
 	/* End of v4 array */
-	s32 v4_end[0];
+	s32 v4_end[];
 };
 
 /*