net: ti: icss-iep: Reject perout generation request

IEP driver supports both perout and pps signal generation
but perout feature is faulty with half-cooked support
due to some missing configuration. Remove perout
support from the driver and reject perout requests with
"not supported" error code.

Fixes: c1e0230e ("net: ti: icss-iep: Add IEP driver")
Signed-off-by: Meghana Malladi <m-malladi@ti.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20250227092441.1848419-1-m-malladi@ti.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>