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/portl2_defconfig b/configs/portl2_defconfig
index 125866d..f9f13af 100644
--- a/configs/portl2_defconfig
+++ b/configs/portl2_defconfig
@@ -4,6 +4,7 @@
 CONFIG_TARGET_KM_KIRKWOOD=y
 CONFIG_IDENT_STRING="\nKeymile Port-L2"
 CONFIG_SYS_EXTRA_OPTIONS="KM_PORTL2"
+CONFIG_MISC_INIT_R=y
 CONFIG_VERSION_VARIABLE=y
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_HUSH_PARSER=y