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/integratorcp_cm926ejs_defconfig b/configs/integratorcp_cm926ejs_defconfig
index 037cd4d..f39f021 100644
--- a/configs/integratorcp_cm926ejs_defconfig
+++ b/configs/integratorcp_cm926ejs_defconfig
@@ -2,6 +2,8 @@
 CONFIG_ARCH_INTEGRATOR=y
 CONFIG_ARCH_INTEGRATOR_CP=y
 CONFIG_CM926EJ_S=y
+CONFIG_USE_BOOTARGS=y
+CONFIG_BOOTARGS="root=/dev/mtdblock0 console=ttyAMA0 console=tty ip=dhcp netdev=27,0,0xfc800000,0xfc800010,eth0 video=clcdfb:0"
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_HUSH_PARSER=y