CVE-2026-43281 mailbox: Prevent out-of-bounds access in fw_mbox_index_xlate()

In the Linux kernel, the following vulnerability has been resolved: mailbox: Prevent out-of-bounds access in fwmboxindexxlate Although it is guided that mbox-cells must be at least 1, there are many instances of mbox-cells = ; in the device tree. If that is the case and the corresponding mailbox...