Convert CONFIG_MISC_INIT_R to Kconfig

This converts the following to Kconfig:
   CONFIG_MISC_INIT_R

Signed-off-by: Adam Ford <aford173@gmail.com>
[trini: Update the defaults logic slightly]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/chromebook_samus_defconfig b/configs/chromebook_samus_defconfig
index 817bb0a..e4c51f8 100644
--- a/configs/chromebook_samus_defconfig
+++ b/configs/chromebook_samus_defconfig
@@ -18,6 +18,7 @@
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="root=/dev/sdb3 init=/sbin/init rootwait ro"
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
+CONFIG_MISC_INIT_R=y
 CONFIG_DISPLAY_BOARDINFO_LATE=y
 CONFIG_LAST_STAGE_INIT=y
 CONFIG_HUSH_PARSER=y