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/ls1046aqds_qspi_defconfig b/configs/ls1046aqds_qspi_defconfig
index fbf4d87..ab9f1d1 100644
--- a/configs/ls1046aqds_qspi_defconfig
+++ b/configs/ls1046aqds_qspi_defconfig
@@ -7,6 +7,8 @@
 CONFIG_QSPI_BOOT=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_BOOTDELAY=10
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="console=ttyS0,115200 root=/dev/ram0 earlycon=uart8250,mmio,0x21c0500 mtdparts=1550000.quadspi:2m(uboot),14m(free)"
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_BOOTZ=y
 # CONFIG_CMD_IMLS is not set