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/sh7763rdp_defconfig b/configs/sh7763rdp_defconfig
index e9dc848..9683c7a 100644
--- a/configs/sh7763rdp_defconfig
+++ b/configs/sh7763rdp_defconfig
@@ -1,4 +1,5 @@
 CONFIG_SH=y
+CONFIG_SYS_TEXT_BASE=0x8FFC0000
 CONFIG_TARGET_SH7763RDP=y
 CONFIG_BOOTDELAY=-1
 CONFIG_USE_BOOTARGS=y