Convert CONFIG_MISC_INIT_F to Kconfig

This converts the following to Kconfig:
   CONFIG_MISC_INIT_F

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/configs/MPC8349ITX_LOWBOOT_defconfig b/configs/MPC8349ITX_LOWBOOT_defconfig
index 46f7afc..cf1e90d 100644
--- a/configs/MPC8349ITX_LOWBOOT_defconfig
+++ b/configs/MPC8349ITX_LOWBOOT_defconfig
@@ -153,6 +153,7 @@
 CONFIG_BOOTDELAY=6
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="root=/dev/nfs rw nfsroot=:/nfsroot/rootfs ip=::::mpc8349emitx:eth0:off console=ttyS0,115200"
+CONFIG_MISC_INIT_F=y
 CONFIG_MISC_INIT_R=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="MPC8349E-mITX> "