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/ten64_tfa_defconfig b/configs/ten64_tfa_defconfig
index c90a560..48b2ffc 100644
--- a/configs/ten64_tfa_defconfig
+++ b/configs/ten64_tfa_defconfig
@@ -1,7 +1,7 @@
 CONFIG_ARM=y
 CONFIG_TARGET_TEN64=y
 CONFIG_TFABOOT=y
-CONFIG_SYS_TEXT_BASE=0x82000000
+CONFIG_TEXT_BASE=0x82000000
 CONFIG_NR_DRAM_BANKS=2
 CONFIG_ENV_SIZE=0x80000
 CONFIG_ENV_OFFSET=0x500000