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/phycore-rk3288_defconfig b/configs/phycore-rk3288_defconfig
index cfe02df..025eb32 100644
--- a/configs/phycore-rk3288_defconfig
+++ b/configs/phycore-rk3288_defconfig
@@ -2,7 +2,7 @@
 CONFIG_SPL_SKIP_LOWLEVEL_INIT_ONLY=y
 CONFIG_SYS_ARCH_TIMER=y
 CONFIG_ARCH_ROCKCHIP=y
-CONFIG_SYS_TEXT_BASE=0x00000000
+CONFIG_TEXT_BASE=0x00000000
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_ENV_OFFSET=0x3F8000
 CONFIG_DEFAULT_DEVICE_TREE="rk3288-phycore-rdk"