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/ls2081ardb_defconfig b/configs/ls2081ardb_defconfig
index a3d29e8..a6aaaf2 100644
--- a/configs/ls2081ardb_defconfig
+++ b/configs/ls2081ardb_defconfig
@@ -2,7 +2,7 @@
 CONFIG_COUNTER_FREQUENCY=25000000
 CONFIG_GIC_V3_ITS=y
 CONFIG_TARGET_LS2081ARDB=y
-CONFIG_SYS_TEXT_BASE=0x20100000
+CONFIG_TEXT_BASE=0x20100000
 CONFIG_SYS_MALLOC_LEN=0x202000
 CONFIG_NR_DRAM_BANKS=3
 CONFIG_ENV_SIZE=0x2000