dmaengine: tegra-apb: Replace zero-length array with flexible-array

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

drivers/dma/tegra20-apb-dma.c

@@ -225,7 +225,7 @@ struct tegra_dma {
 	u32				global_pause_count;
 
 	/* Last member of the structure */
-	struct tegra_dma_channel channels[0];
+	struct tegra_dma_channel channels[];
 };
 
 static inline void tdma_write(struct tegra_dma *tdma, u32 reg, u32 val)