rockchip: rk3566-anbernic-rgxx3: Rename defconfig to include SoC name

Rename defconfig to include SoC name, use similar pattern as other
RK356x boards: <soc>-<name>.dts -> <name>-<soc>_defconfig

Suggested-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/doc/board/rockchip/rockchip.rst b/doc/board/rockchip/rockchip.rst
index 4668e59..de9fe8e 100644
--- a/doc/board/rockchip/rockchip.rst
+++ b/doc/board/rockchip/rockchip.rst
@@ -91,7 +91,7 @@
      - Theobroma Systems RK3399-Q7 SoM - Puma (puma_rk3399)
 
 * rk3566
-     - Anbernic RGxx3 (anbernic-rgxx3)
+     - Anbernic RGxx3 (anbernic-rgxx3-rk3566)
      - Pine64 Quartz64-A Board (quartz64-a-rk3566)
      - Pine64 Quartz64-B Board (quartz64-b-rk3566)
      - Pine64 SOQuartz on Blade (soquartz-blade-rk3566)