Convert CONFIG_USE_PREBOOT and CONFIG_PREBOOT to Kconfig

This converts the following to Kconfig:
   CONFIG_USE_PREBOOT
   CONFIG_PREBOOT

Both are together in one commit, since otherwise the former causes kconfig
to define the latter, which gives duplicate symbol errors.

Includes a manual fixup for CONFIG_PREBOOT in ids8313_defconfig since the
backslash lands in the wrong place. Similarly with socfpga_vining_fpga.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/fennec-rk3288_defconfig b/configs/fennec-rk3288_defconfig
index 16d8fb1..ab0facc 100644
--- a/configs/fennec-rk3288_defconfig
+++ b/configs/fennec-rk3288_defconfig
@@ -10,6 +10,7 @@
 CONFIG_DEBUG_UART_CLOCK=24000000
 CONFIG_DEBUG_UART=y
 # CONFIG_ANDROID_BOOT_IMAGE is not set
+CONFIG_USE_PREBOOT=y
 CONFIG_SILENT_CONSOLE=y
 CONFIG_CONSOLE_MUX=y
 CONFIG_DEFAULT_FDT_FILE="rk3288-fennec.dtb"
@@ -79,6 +80,5 @@
 CONFIG_USB_HOST_ETHER=y
 CONFIG_USB_ETHER_ASIX=y
 CONFIG_USB_ETHER_SMSC95XX=y
-CONFIG_USE_TINY_PRINTF=y
 CONFIG_CMD_DHRYSTONE=y
 CONFIG_ERRNO_STR=y