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/net2big_v2_defconfig b/configs/net2big_v2_defconfig
index 8eb91f1..89921a54 100644
--- a/configs/net2big_v2_defconfig
+++ b/configs/net2big_v2_defconfig
@@ -10,6 +10,7 @@
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="console=ttyS0,115200"
 CONFIG_CONSOLE_MUX=y
+CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="2big2> "