net: pcs: rzn1-miic: Add RZ/T2H MIIC support

Add support for the Renesas RZ/T2H MIIC by defining SoC-specific
modctrl match tables, register map, and string representations
for converters and ports.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://patch.msgid.link/20250910204132.319975-10-prabhakar.mahadev-lad.rj@bp.renesas.com


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