realtek: rtl930x: adapt kernel configuration

realtek: rtl930x: adapt kernel configuration

The RTL93xx based D-Link DGS-1250 series is currently being
prepared for OpenWrt support. These devices have some extras
that are not yet supported by the existing configuration.
Add the following items to the kernel configuration:

- CONFIG_SENSORS_GPIO_FAN: The devices have a simple gpio
  controlled fan (0/1 aka off/on).
- CONFIG_I2C_GPIO_SHARED: The busses of the SFP+ slots are
  not controlled by the built-in SOC I2C controller. Instead
  they are realized by shared SCL bit banged GPIOs.
- CONFIG_EEPROM_AT24: The MAC address and other device data
  is storend in an Atmel EEPROM.

Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
Link: https://github.com/openwrt/openwrt/pull/22543
Signed-off-by: Robert Marko <robimarko@gmail.com>