firmware: thead: Fix buffer overflow and use standard endian macros

Summary

In the Linux kernel, the following vulnerability has been resolved: firmware: thead: Fix buffer overflow and use standard endian macros Addresses two issues in the TH1520 AON firmware protocol driver: 1. Fix a potential buffer overflow where the code used unsafe pointer arithmetic to access the 'mode' field through the 'resource' pointer with an offset. This was flagged by Smatch static checker as: "buffer overflow 'data' 2 <= 3" 2. Replace custom RPC_SET_BE* and RPC_GET_BE* macros with standard kernel endianness conversion macros (cpu_to_be16, etc.) for better portability and maintainability. The functionality was re-tested with the GPU power-up sequence, confirming the GPU powers up correctly and the driver probes successfully. [ 12.702370] powervr ffef400000.gpu: [drm] loaded firmware powervr/rogue_36.52.104.182_v1.fw [ 12.711043] powervr ffef400000.gpu: [drm] FW version v1.0 (build 6645434 OS) [ 12.719787] [drm] Initialized powervr 1.0.0 for ffef400000.gpu on minor 0