net: ti: icssm-prueth: Adds link detection, RX and TX support.

net: ti: icssm-prueth: Adds link detection, RX and TX support.

Changes corresponding to link configuration such as speed and duplexity.
IRQ and handler initializations are performed for packet reception.Firmware
receives the packet from the wire and stores it into OCMC queue. Next, it
notifies the CPU via interrupt. Upon receiving the interrupt CPU will
service the IRQ and packet will be processed by pushing the newly allocated
SKB to upper layers.

When the user application want to transmit a packet, it will invoke
sys_send() which will in turn invoke the PRUETH driver, then it will write
the packet into OCMC queues. PRU firmware will pick up the packet and
transmit it on to the wire.

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/20250912115443.529856-5-parvathi@couthit.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>