configs: visionfive2: Enable CONFIG_OF_BOARD_SETUP

Enable CONFIG_OF_BOARD_SETUP, so we could use ft_board_setup() to fixup
memory size passed to kernel.

Signed-off-by: Shengyu Qu <wiagn233@outlook.com>
Tested-by: Milan P. Stanić <mps@arvanta.net>
diff --git a/configs/starfive_visionfive2_defconfig b/configs/starfive_visionfive2_defconfig
index 9df6fce..8abe645 100644
--- a/configs/starfive_visionfive2_defconfig
+++ b/configs/starfive_visionfive2_defconfig
@@ -36,6 +36,7 @@
 CONFIG_ARCH_RV64I=y
 CONFIG_CMODEL_MEDANY=y
 CONFIG_RISCV_SMODE=y
+CONFIG_OF_BOARD_SETUP=y
 # CONFIG_OF_BOARD_FIXUP is not set
 CONFIG_FIT=y
 CONFIG_DISTRO_DEFAULTS=y