net: rswitch: Add Renesas R-Car X5H Ethernet Switch3 support

net: rswitch: Add Renesas R-Car X5H Ethernet Switch3 support

Add support for the Renesas Ethernet Switch3 (RSW3) controller,
present in R-Car Gen5 SoCs such as R-Car X5H (R8A78000). The
hardware offset differences are handled via driver match data.

The driver newly detects whether the switch prot is connected
to xPCS or not, and if so, turns on MIOC bit 3. This is new on
R-Car X5H. GWCKSC register is also programmed only on X5H. The
rest of the operation is identical to RSwitch2.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Signed-off-by: Tam Nguyen <tam.nguyen.xa@renesas.com>
Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com>
Signed-off-by: Thanh Quan <thanh.quan.xn@renesas.com>
Signed-off-by: Hai Pham <hai.pham.ud@renesas.com>