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/tbs2910_defconfig b/configs/tbs2910_defconfig
index 5adcd9d..9420c27 100644
--- a/configs/tbs2910_defconfig
+++ b/configs/tbs2910_defconfig
@@ -1,6 +1,7 @@
 CONFIG_ARM=y
 CONFIG_SYS_THUMB_BUILD=y
 CONFIG_ARCH_MX6=y
+CONFIG_SYS_TEXT_BASE=0x17800000
 CONFIG_TARGET_TBS2910=y
 CONFIG_CMD_HDMIDETECT=y
 CONFIG_FIT=y