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/am57xx_hs_evm_defconfig b/configs/am57xx_hs_evm_defconfig
index 2f233e5..8957192 100644
--- a/configs/am57xx_hs_evm_defconfig
+++ b/configs/am57xx_hs_evm_defconfig
@@ -23,6 +23,7 @@
 CONFIG_BOOTARGS="androidboot.serialno=${serial#} console=ttyS2,115200 androidboot.console=ttyS2 androidboot.hardware=am57xevmboard"
 # CONFIG_USE_BOOTCOMMAND is not set
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
+# CONFIG_MISC_INIT_R is not set
 CONFIG_VERSION_VARIABLE=y
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y