drm/amd/pm: Replace one-element array with flexible-array member in struct vi_dpm_table

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].

Use a flexible-array member in struct vi_dpm_table instead of a
one-element array.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/5f7c433c.TTk9rnA+F58kyDUy%25lkp@intel.com/
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/inc/hwmgr.h

@@ -60,7 +60,7 @@ struct vi_dpm_level {
 
 struct vi_dpm_table {
 	uint32_t count;
-	struct vi_dpm_level dpm_level[1];
+	struct vi_dpm_level dpm_level[];
 };
 
 #define PCIE_PERF_REQ_REMOVE_REGISTRY   0