Convert CONFIG_ARCH_MISC_INIT to Kconfig

This converts the following to Kconfig:
   CONFIG_ARCH_MISC_INIT

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/colibri_t20_defconfig b/configs/colibri_t20_defconfig
index a543246..b5460cc 100644
--- a/configs/colibri_t20_defconfig
+++ b/configs/colibri_t20_defconfig
@@ -6,6 +6,7 @@
 CONFIG_OF_SYSTEM_SETUP=y
 CONFIG_SYS_STDIO_DEREGISTER=y
 # CONFIG_DISPLAY_BOARDINFO is not set
+CONFIG_ARCH_MISC_INIT=y
 CONFIG_SYS_PROMPT="Colibri T20 # "
 # CONFIG_CMD_IMI is not set
 # CONFIG_CMD_IMLS is not set