net: ti: icssm-prueth: Adds IEP support for PRUETH on AM33x, AM43x and AM57x SOCs

net: ti: icssm-prueth: Adds IEP support for PRUETH on AM33x, AM43x and AM57x SOCs

Added API hooks for IEP module (legacy 32-bit model) to support
timestamping requests from application.

Reviewed-by: Mohan Reddy Putluru <pmohan@couthit.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Basharath Hussain Khaja <basharath@couthit.com>
Signed-off-by: Parvathi Pudi <parvathi@couthit.com>
Link: https://patch.msgid.link/20250912115443.529856-6-parvathi@couthit.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>