misc: ti_fpc202: Switch to of_fwnode_handle()

misc: ti_fpc202: Switch to of_fwnode_handle()

of_node_to_fwnode() is an irqdomain's reimplementation of the
"officially" defined of_fwnode_handle(). The former is in the process of
being removed, so use the latter instead.

This is the last in-tree user.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Fixes: 1e5c9b1efa1c ("misc: add FPC202 dual port controller driver")
Reviewed-by: Romain Gantois <romain.gantois@bootlin.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20250723053516.1796097-1-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>