ptp: ocp: Fix NULL dereference in Adva board SMA sysfs operations

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: ptp: ocp: Fix NULL dereference in Adva board SMA sysfs operations On Adva boards, SMA sysfs store/get operations can call __handle_signal_outputs() or __handle_signal_inputs() while the `irig` and `dcf` pointers are uninitialized, leading to a NULL pointer dereference in __handle_signal() and causing a kernel crash. Adva boards don't use `irig` or `dcf` functionality, so add Adva-specific callbacks `ptp_ocp_sma_adva_set_outputs()` and `ptp_ocp_sma_adva_set_inputs()` that avoid invoking `irig` or `dcf` input/output routines.

References

• https://git.kernel.org/stable/c/8a543d825e78b8d680d8f891381b83fbffdb0bb6
• https://git.kernel.org/stable/c/5b349f9cdb4a9daa133bea267dfc0c383628387a
• https://git.kernel.org/stable/c/e98386d79a23c57cf179fe4138322e277aa3aa74