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/rpi_4_32b_defconfig b/configs/rpi_4_32b_defconfig
index 8c03252..5207e56 100644
--- a/configs/rpi_4_32b_defconfig
+++ b/configs/rpi_4_32b_defconfig
@@ -1,6 +1,6 @@
 CONFIG_ARM=y
 CONFIG_ARCH_BCM283X=y
-CONFIG_SYS_TEXT_BASE=0x00008000
+CONFIG_TEXT_BASE=0x00008000
 CONFIG_TARGET_RPI_4_32B=y
 CONFIG_ENV_SIZE=0x4000
 CONFIG_DEFAULT_DEVICE_TREE="bcm2711-rpi-4-b"