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/xtfpga_defconfig b/configs/xtfpga_defconfig
index 759b4a5..77354fe 100644
--- a/configs/xtfpga_defconfig
+++ b/configs/xtfpga_defconfig
@@ -2,6 +2,7 @@
 CONFIG_SYS_CPU="dc233c"
 CONFIG_XTFPGA_KC705=y
 CONFIG_BOOTDELAY=10
+CONFIG_MISC_INIT_R=y
 CONFIG_VERSION_VARIABLE=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="U-Boot> "