common: Move CONFIG_BOOTARGS to Kconfig

Also introduce CONFIG_USE_BOOTARGS option so we can control if
CONFIG_BOOTARGS defined at all.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
[trini: Resync r8a779[56]_ulcb, various ls10xx targets]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/smdkc100_defconfig b/configs/smdkc100_defconfig
index 82ba51c..76cefed 100644
--- a/configs/smdkc100_defconfig
+++ b/configs/smdkc100_defconfig
@@ -5,6 +5,8 @@
 CONFIG_DEFAULT_DEVICE_TREE="s5pc1xx-smdkc100"
 CONFIG_ENV_IS_IN_ONENAND=y
 CONFIG_BOOTDELAY=3
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="root=/dev/mtdblock5 ubi.mtd=4 rootfstype=cramfs console=ttySAC0,115200n8 mem=128M  mtdparts=s3c-onenand:256k(bootloader),128k@0x40000(params),3m@0x60000(kernel),16m@0x360000(test),-(UBI)"
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="SMDKC100 # "
 # CONFIG_CMD_IMLS is not set