Rename CONFIG_SYS_TEXT_BASE to CONFIG_TEXT_BASE

The current name is inconsistent with SPL which uses CONFIG_SPL_TEXT_BASE
and this makes it imposible to use CONFIG_VAL().

Rename it to resolve this problem.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/meesc.h b/include/configs/meesc.h
index 6b22967..cffcd9d 100644
--- a/include/configs/meesc.h
+++ b/include/configs/meesc.h
@@ -21,7 +21,7 @@
 #include <asm/hardware.h>
 
 /*
- * Warning: changing CONFIG_SYS_TEXT_BASE requires
+ * Warning: changing CONFIG_TEXT_BASE requires
  * adapting the initial boot program.
  * Since the linker has to swallow that define, we must use a pure
  * hex number here!