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_defconfig b/configs/ls1088aqds_defconfig
index 51e5622..5905995 100644
--- a/configs/ls1088aqds_defconfig
+++ b/configs/ls1088aqds_defconfig
@@ -19,6 +19,8 @@
 CONFIG_OF_STDOUT_VIA_ALIAS=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="fsl_mc lazyapply dpl 0x580d00000 && cp.b $kernel_start $kernel_load $kernel_size && bootm $kernel_load"
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_DISPLAY_BOARDINFO_LATE=y
 CONFIG_HUSH_PARSER=y