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/Kconfig b/Kconfig
index d297513..ef94f88 100644
--- a/Kconfig
+++ b/Kconfig
@@ -274,7 +274,7 @@
 config CUSTOM_SYS_INIT_SP_ADDR
 	hex "Static location for the initial stack pointer"
 	depends on HAS_CUSTOM_SYS_INIT_SP_ADDR
-	default SYS_TEXT_BASE if TFABOOT
+	default TEXT_BASE if TFABOOT
 
 config SYS_MALLOC_F
 	bool "Enable malloc() pool before relocation"