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/MPC8536DS_SPIFLASH_defconfig b/configs/MPC8536DS_SPIFLASH_defconfig
index 7efcb66..1671da1 100644
--- a/configs/MPC8536DS_SPIFLASH_defconfig
+++ b/configs/MPC8536DS_SPIFLASH_defconfig
@@ -8,6 +8,7 @@
 CONFIG_SYS_EXTRA_OPTIONS="SPIFLASH"
 CONFIG_BOOTDELAY=10
 # CONFIG_CONSOLE_MUX is not set
+# CONFIG_MISC_INIT_R is not set
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_BOARD_EARLY_INIT_R=y
 CONFIG_HUSH_PARSER=y