net: ti: icss-iep: Fix possible NULL pointer dereference for perout request

In the Linux kernel, the following vulnerability has been resolved:

net: ti: icss-iep: Fix possible NULL pointer dereference for perout request

The ICSS IEP driver tracks perout and pps enable state with flags.

Currently when disabling pps and perout signals during icss_iep_exit(),

results in NULL pointer dereference for perout.

To fix the null pointer dereference issue, the icss_iep_perout_enable_hw

function can be modified to directly clear the IEP CMP registers when

disabling PPS or PEROUT, without referencing the ptp_perout_request

structure, as its contents are irrelevant in this case.