Convert CONFIG_USE_BOOTCOMMAND et al to Kconfig

This converts the following to Kconfig:
   CONFIG_USE_BOOTCOMMAND
   CONFIG_BOOTCOMMAND
   CONFIG_RAMBOOTCOMMAND
   CONFIG_NFSBOOTCOMMAND

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/socfpga_secu1_defconfig b/configs/socfpga_secu1_defconfig
index db48006..cc15644 100644
--- a/configs/socfpga_secu1_defconfig
+++ b/configs/socfpga_secu1_defconfig
@@ -19,7 +19,7 @@
 CONFIG_FIT=y
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="console=ttyS0,115200 ubi.fm_autoconvert=1 uio_pdrv_genirq.of_id=\"idq,regbank\""
-# CONFIG_USE_BOOTCOMMAND is not set
+CONFIG_BOOTCOMMAND="setenv bootcmd 'bridge enable; if test ${bootnum} = 'b'; then run _fpga_loadsafe; else if test ${bootcount} -eq 4; then echo 'Switching copy...'; setexpr x $bootnum % 2 && setexpr bootnum $x + 1; saveenv; fi; run _fpga_loaduser; fi;echo 'Booting bank $bootnum' && run userload && run userboot;' && setenv altbootcmd 'setenv bootnum b && saveenv && boot;' && saveenv && saveenv && boot;"
 CONFIG_DEFAULT_FDT_FILE="socfpga_arria5_secu1.dtb"
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE=y