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/taurus_defconfig b/configs/taurus_defconfig
index 1f47241..344207c 100644
--- a/configs/taurus_defconfig
+++ b/configs/taurus_defconfig
@@ -4,6 +4,7 @@
 # CONFIG_SPL_USE_ARCH_MEMSET is not set
 CONFIG_ARCH_AT91=y
 CONFIG_SPL_LDSCRIPT="arch/$(ARCH)/cpu/u-boot-spl.lds"
+CONFIG_SYS_TEXT_BASE=0x21000000
 CONFIG_TARGET_TAURUS=y
 CONFIG_SPL_GPIO_SUPPORT=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y