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/P5040DS_defconfig b/configs/P5040DS_defconfig
index 7c94ecb..fbde5dc 100644
--- a/configs/P5040DS_defconfig
+++ b/configs/P5040DS_defconfig
@@ -1,4 +1,5 @@
 CONFIG_PPC=y
+CONFIG_SYS_TEXT_BASE=0xEFF40000
 CONFIG_MPC85xx=y
 CONFIG_TARGET_P5040DS=y
 CONFIG_FIT=y