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/am335x_baltos_defconfig b/configs/am335x_baltos_defconfig
index cffcccb..971e7ef 100644
--- a/configs/am335x_baltos_defconfig
+++ b/configs/am335x_baltos_defconfig
@@ -21,6 +21,7 @@
 CONFIG_SYS_EXTRA_OPTIONS="NAND"
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 CONFIG_VERSION_VARIABLE=y
+CONFIG_ARCH_MISC_INIT=y
 CONFIG_SPL=y
 CONFIG_SPL_STACK_R=y
 CONFIG_SPL_MTD_SUPPORT=y