configs: Migrate CONFIG_SYS_TEXT_BASE

On the NIOS2 and Xtensa architectures, we do not have
CONFIG_SYS_TEXT_BASE set.  This is a strict migration of the current
values into the defconfig and removing them from the headers.

I did not attempt to add more default values in and for now will leave
that to maintainers.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/kzm9g_defconfig b/configs/kzm9g_defconfig
index 6271aa0..0469c3b 100644
--- a/configs/kzm9g_defconfig
+++ b/configs/kzm9g_defconfig
@@ -1,6 +1,7 @@
 CONFIG_ARM=y
 # CONFIG_SYS_THUMB_BUILD is not set
 CONFIG_ARCH_RMOBILE=y
+CONFIG_SYS_TEXT_BASE=0x00000000
 CONFIG_TARGET_KZM9G=y
 CONFIG_BOOTDELAY=3
 CONFIG_USE_BOOTARGS=y