rockchip: rk3328-nanopi-r2: Update defconfig

Update defconfig for rk3328-nanopi-r2* boards with new defaults.

Remove the SPL_DRIVERS_MISC=y option, no misc driver is used in SPL.

Add CONFIG_SPL_FIT_SIGNATURE=y to let SPL verify an auto generated hash
of FIT images. This help indicate if there is an issue loading any of
the images to DRAM or SRAM. Also add LEGACY_IMAGE_FORMAT=y to keep
support for scripts.

Remove SPL_I2C=y and SPL_PMIC_RK8XX=y, the related i2c and pmic nodes is
not included in the SPL fdt.

Add CMD_GPIO=y and CMD_REGULATOR=y to add the helpful gpio and regulator
commands.

Add ROCKCHIP_EFUSE=y and remove NET_RANDOM_ETHADDR=y, ethaddr and
eth1addr is set based on cpuid read from eFUSE.

Add SPL_DM_SEQ_ALIAS=y option to use alias sequence number in SPL.

Add DM_ETH_PHY=y, PHY_GIGE=y, PHY_MOTORCOMM=y, PHY_REALTEK=y and remove
&gmac2io to support reset of onboard ethernet PHYs. Also add DM_MDIO=y
to ensure device tree props is used by motorcomm PHY driver.

Remove REGULATOR_PWM=y, the pwm-regulator compatible is not used.

Add DM_REGULATOR_GPIO=y and SPL_DM_REGULATOR_GPIO=y to support the
regulator-gpio compatible.

Add RNG_ROCKCHIP=y and DM_RNG=y options to support the onboard random
generator.

Also add missing device tree files to MAINTAINERS file.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Tianling Shen <cnsztl@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/doc/board/rockchip/rockchip.rst b/doc/board/rockchip/rockchip.rst
index c8ba8ff..3f7a5dc 100644
--- a/doc/board/rockchip/rockchip.rst
+++ b/doc/board/rockchip/rockchip.rst
@@ -61,6 +61,9 @@
 * rk3328
      - Rockchip Evb-RK3328 (evb-rk3328)
      - Firefly ROC-RK3328-CC (roc-cc-rk3328)
+     - FriendlyElec NanoPi R2C (nanopi-r2c-rk3328)
+     - FriendlyElec NanoPi R2C Plus (nanopi-r2c-plus-rk3328)
+     - FriendlyElec NanoPi R2S (nanopi-r2s-rk3328)
      - Pine64 Rock64 (rock64-rk3328)
      - Radxa ROCK Pi E (rock-pi-e-rk3328)
 * rk3368