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/configs/colibri_vf_defconfig b/configs/colibri_vf_defconfig
index d576434..3352b8e 100644
--- a/configs/colibri_vf_defconfig
+++ b/configs/colibri_vf_defconfig
@@ -2,7 +2,7 @@
 CONFIG_SKIP_LOWLEVEL_INIT=y
 CONFIG_SYS_THUMB_BUILD=y
 CONFIG_ARCH_VF610=y
-CONFIG_SYS_TEXT_BASE=0x3f401000
+CONFIG_TEXT_BASE=0x3f401000
 CONFIG_SYS_MALLOC_LEN=0x0220000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_SIZE=0x20000