CVE-2025-40299 gve: Implement gettimex64 with -EOPNOTSUPP

In the Linux kernel, the following vulnerability has been resolved: gve: Implement gettimex64 with -EOPNOTSUPP gve implemented a ptpclock for sole use of doauxwork at this time. ptpclockgettime and ptpsysoffset assume every ptpclock has implemented either gettimex64 or gettime64. Stub gettimex64...