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/socfpga_agilex_defconfig b/configs/socfpga_agilex_defconfig
index 0603dd1..e5864eb 100644
--- a/configs/socfpga_agilex_defconfig
+++ b/configs/socfpga_agilex_defconfig
@@ -1,7 +1,7 @@
 CONFIG_ARM=y
 CONFIG_COUNTER_FREQUENCY=400000000
 CONFIG_ARCH_SOCFPGA=y
-CONFIG_SYS_TEXT_BASE=0x1000
+CONFIG_TEXT_BASE=0x1000
 CONFIG_SYS_MALLOC_LEN=0x500000
 CONFIG_NR_DRAM_BANKS=2
 CONFIG_ENV_SIZE=0x1000