atstk100x: move CONFIG_SYS_TEXT_BASE to header

Signed-off-by: Andreas Bießmann <biessmann@corscience.de>
diff --git a/include/configs/atstk1006.h b/include/configs/atstk1006.h
index d681929..2cff140 100644
--- a/include/configs/atstk1006.h
+++ b/include/configs/atstk1006.h
@@ -173,6 +173,7 @@
 #define CONFIG_SYS_MAX_FLASH_SECT		135
 
 #define CONFIG_SYS_MONITOR_BASE		CONFIG_SYS_FLASH_BASE
+#define CONFIG_SYS_TEXT_BASE		0x00000000
 
 #define CONFIG_SYS_INTRAM_BASE			INTERNAL_SRAM_BASE
 #define CONFIG_SYS_INTRAM_SIZE			INTERNAL_SRAM_SIZE