interconnect: icc-clk: Annotate struct icc_clk_provider with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct icc_clk_provider.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Georgi Djakov <djakov@kernel.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230817202914.never.661-kees@kernel.org
Signed-off-by: Georgi Djakov <djakov@kernel.org>

Author: kees

drivers/interconnect/icc-clk.c

@@ -16,7 +16,7 @@ struct icc_clk_node {
 struct icc_clk_provider {
 	struct icc_provider provider;
 	int num_clocks;
-	struct icc_clk_node clocks[];
+	struct icc_clk_node clocks[] __counted_by(num_clocks);
 };
 
 #define to_icc_clk_provider(_provider) \