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/nanopi-m4b-rk3399_defconfig b/configs/nanopi-m4b-rk3399_defconfig
index 497385f..d02eb18 100644
--- a/configs/nanopi-m4b-rk3399_defconfig
+++ b/configs/nanopi-m4b-rk3399_defconfig
@@ -2,7 +2,7 @@
 CONFIG_SKIP_LOWLEVEL_INIT=y
 CONFIG_COUNTER_FREQUENCY=24000000
 CONFIG_ARCH_ROCKCHIP=y
-CONFIG_SYS_TEXT_BASE=0x00200000
+CONFIG_TEXT_BASE=0x00200000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_OFFSET=0x3F8000
 CONFIG_DEFAULT_DEVICE_TREE="rk3399-nanopi-m4b"