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/usb_a9263_dataflash_defconfig b/configs/usb_a9263_dataflash_defconfig
index 9cc51ec..d0cfc481 100644
--- a/configs/usb_a9263_dataflash_defconfig
+++ b/configs/usb_a9263_dataflash_defconfig
@@ -6,6 +6,8 @@
 CONFIG_SYS_EXTRA_OPTIONS="AT91SAM9263,SYS_USE_DATAFLASH"
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_BOOTDELAY=3
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="console=ttyS0,115200 root=/dev/mtdblock1 mtdparts=mtdparts=atmel_nand:16m(kernel)ro,120m(root1),-(root2) rw rootfstype=jffs2"
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="U-Boot> "