Convert CONFIG_BOOT_RETRY_TIME et al to Kconfig

This converts the following to Kconfig:
   CONFIG_BOOT_RETRY_TIME
   CONFIG_BOOT_RETRY_MIN
   CONFIG_RESET_TO_RETRY

We also introduce CONFIG_BOOT_RETRY to gate these options, and clean up
the associated Makefile entry and C code for picking default values of
CONFIG_BOOT_RETRY_MIN.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/highbank_defconfig b/configs/highbank_defconfig
index 61a25c2..f8cf18e 100644
--- a/configs/highbank_defconfig
+++ b/configs/highbank_defconfig
@@ -17,6 +17,9 @@
 CONFIG_AUTOBOOT_KEYED=y
 CONFIG_AUTOBOOT_PROMPT="Autobooting in %d seconds...\nPress <s> to stop or <d> to delay\n"
 CONFIG_AUTOBOOT_KEYED_CTRLC=y
+CONFIG_BOOT_RETRY=y
+CONFIG_BOOT_RETRY_TIME=-1
+CONFIG_RESET_TO_RETRY=y
 # CONFIG_USE_BOOTCOMMAND is not set
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set