net: dsa: b53: hide legacy gpiolib usage on non-mips

net: dsa: b53: hide legacy gpiolib usage on non-mips

The MIPS bcm53xx platform still uses the legacy gpiolib interfaces based
on gpio numbers, but other platforms do not.

Hide these interfaces inside of the existing #ifdef block and use the
modern interfaces in the common parts of the driver to allow building
it when the gpio_set_value() is left out of the kernel.

Reviewed-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260601165716.648230-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>