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/apf27_defconfig b/configs/apf27_defconfig
index 549556d..11061c6 100644
--- a/configs/apf27_defconfig
+++ b/configs/apf27_defconfig
@@ -6,6 +6,8 @@
 CONFIG_IDENT_STRING=" apf27 patch 3.10"
 CONFIG_ENV_IS_IN_NAND=y
 CONFIG_BOOTDELAY=5
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="console=ttySMX0,115200 mtdparts=mxc_nand.0:1M(u-boot)ro,512K(env),512K(env2),512K(firmware),512K(dtb),5M(kernel),-(rootfs) ubi.mtd=rootfs root=ubi0:rootfs rootfstype=ubifs "
 CONFIG_VERSION_VARIABLE=y
 CONFIG_SPL=y
 CONFIG_HUSH_PARSER=y