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/sama5d2_ptc_ek_mmc_defconfig b/configs/sama5d2_ptc_ek_mmc_defconfig
index a59a4e3..3cbd06e 100644
--- a/configs/sama5d2_ptc_ek_mmc_defconfig
+++ b/configs/sama5d2_ptc_ek_mmc_defconfig
@@ -15,6 +15,7 @@
 CONFIG_SD_BOOT=y
 CONFIG_BOOTDELAY=3
 CONFIG_CONSOLE_MUX=y
+CONFIG_MISC_INIT_R=y
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_BOOTZ=y