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/ls1088aqds_sdcard_ifc_defconfig b/configs/ls1088aqds_sdcard_ifc_defconfig
index 5a85ac4..acb951c 100644
--- a/configs/ls1088aqds_sdcard_ifc_defconfig
+++ b/configs/ls1088aqds_sdcard_ifc_defconfig
@@ -25,6 +25,8 @@
 CONFIG_SD_BOOT=y
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="console=ttyS0,115200 root=/dev/ram0 earlycon=uart8250,mmio,0x21c0500 ramdisk_size=0x3000000 default_hugepagesz=2m hugepagesz=2m hugepages=256"
+CONFIG_USE_BOOTCOMMAND=y
+CONFIG_BOOTCOMMAND="mmcinfo;mmc read 0x80001000 0x6800 0x800; fsl_mc lazyapply dpl 0x80001000 && mmc read $kernel_load $kernel_start $kernel_size && bootm $kernel_load"
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_DISPLAY_BOARDINFO_LATE=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR=y