Input: ims-pcu - annotate struct ims_pcu_flash_fmt with __counted_by

Input: ims-pcu - annotate struct ims_pcu_flash_fmt with __counted_by

Use the __counted_by compiler attribute for the data[] flexible array
member to improve the results of array bound sanitizers.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20240619-ims-pcu-counted_by-v1-1-3ee0ead2e57d@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>