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_nand_defconfig b/configs/ls1046aqds_nand_defconfig
index 9292878..96c2838 100644
--- a/configs/ls1046aqds_nand_defconfig
+++ b/configs/ls1046aqds_nand_defconfig
@@ -8,6 +8,8 @@
 CONFIG_NAND_BOOT=y
 CONFIG_ENV_IS_IN_NAND=y
 CONFIG_BOOTDELAY=10
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="console=ttyS0,115200 root=/dev/ram0 earlycon=uart8250,mmio,0x21c0500 mtdparts=60000000.nor:2m@0x100000(nor_bank0_uboot),40m@0x1100000(nor_bank0_fit),7m(nor_bank0_user),2m@0x4100000(nor_bank4_uboot),40m@0x5100000(nor_bank4_fit),-(nor_bank4_user);7e800000.flash:4m(nand_uboot),36m(nand_kernel),472m(nand_free);spi0.0:2m(uboot),14m(free)"
 CONFIG_SPL=y
 CONFIG_SPL_BOARD_INIT=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_SECTOR=y