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/zynq_cse_qspi_defconfig b/configs/zynq_cse_qspi_defconfig
index 8f9ba07..e12306f 100644
--- a/configs/zynq_cse_qspi_defconfig
+++ b/configs/zynq_cse_qspi_defconfig
@@ -16,6 +16,7 @@
 CONFIG_SYS_CUSTOM_LDSCRIPT=y
 CONFIG_SYS_LDSCRIPT="arch/arm/mach-zynq/u-boot.lds"
 # CONFIG_ARCH_FIXUP_FDT_MEMORY is not set
+CONFIG_USE_PREBOOT=y
 # CONFIG_BOARD_LATE_INIT is not set
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_ARCH_EARLY_INIT_R is not set