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/netspace_mini_v2_defconfig b/configs/netspace_mini_v2_defconfig
index ce80497..dda3b6b 100644
--- a/configs/netspace_mini_v2_defconfig
+++ b/configs/netspace_mini_v2_defconfig
@@ -4,7 +4,7 @@
 CONFIG_ARCH_CPU_INIT=y
 CONFIG_ARCH_KIRKWOOD=y
 CONFIG_SYS_KWD_CONFIG="board/LaCie/netspace_v2/kwbimage-ns2l.cfg"
-CONFIG_SYS_TEXT_BASE=0x600000
+CONFIG_TEXT_BASE=0x600000
 CONFIG_NR_DRAM_BANKS=2
 CONFIG_TARGET_NETSPACE_V2=y
 CONFIG_NETSPACE_MINI_V2=y