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/ipam390_defconfig b/configs/ipam390_defconfig
index f131852..8554ff7 100644
--- a/configs/ipam390_defconfig
+++ b/configs/ipam390_defconfig
@@ -8,6 +8,7 @@
 CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL=y
 CONFIG_NR_DRAM_BANKS=1
+CONFIG_MISC_INIT_R=y
 CONFIG_VERSION_VARIABLE=y
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set