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/malta_defconfig b/configs/malta_defconfig
index 98e4770..efb57e6 100644
--- a/configs/malta_defconfig
+++ b/configs/malta_defconfig
@@ -2,6 +2,7 @@
 CONFIG_SYS_TEXT_BASE=0xBE000000
 CONFIG_TARGET_MALTA=y
 CONFIG_DEFAULT_DEVICE_TREE="mti,malta"
+CONFIG_MISC_INIT_R=y
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="malta # "