board: rockchip: Add rk3308 evb support

Add support for rk3308 evaluation board.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/board/rockchip/evb_rk3308/MAINTAINERS b/board/rockchip/evb_rk3308/MAINTAINERS
new file mode 100644
index 0000000..0af119a
--- /dev/null
+++ b/board/rockchip/evb_rk3308/MAINTAINERS
@@ -0,0 +1,6 @@
+EVB-RK3308
+M:      Andy Yan <andy.yan@rock-chips.com>
+S:      Maintained
+F:      board/rockchip/evb_rk3308
+F:      include/configs/evb_rk3308.h
+F:      configs/evb-rk3308_defconfig