drm/panthor: validate firmware interface structure sizes

In the Linux kernel, the following vulnerability has been resolved: drm/panthor: validate firmware interface structure sizes iface_fw_to_cpu_addr() only checks that the firmware-provided MCU virtual address points inside the shared section. The returned pointer is later used as a full firmware interface structure, so accepting an address near the end of the shared section can still lead to out-of-bounds accesses. Pass the expected object size to iface_fw_to_cpu_addr() and reject ranges that do not fit entirely in the shared section.