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/rpi_0_w_defconfig b/configs/rpi_0_w_defconfig
index 75699fa..04717d5 100644
--- a/configs/rpi_0_w_defconfig
+++ b/configs/rpi_0_w_defconfig
@@ -1,5 +1,6 @@
 CONFIG_ARM=y
 CONFIG_ARCH_BCM283X=y
+CONFIG_SYS_TEXT_BASE=0x00008000
 CONFIG_TARGET_RPI_0_W=y
 CONFIG_DEFAULT_DEVICE_TREE="bcm2835-rpi-zero-w"
 CONFIG_DISTRO_DEFAULTS=y