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/board/emulation/qemu-arm/Kconfig b/board/emulation/qemu-arm/Kconfig
index 95dbefa..ed99496 100644
--- a/board/emulation/qemu-arm/Kconfig
+++ b/board/emulation/qemu-arm/Kconfig
@@ -1,6 +1,6 @@
 if TARGET_QEMU_ARM_32BIT || TARGET_QEMU_ARM_64BIT
 
-config SYS_TEXT_BASE
+config TEXT_BASE
 	default 0x00000000
 
 config BOARD_SPECIFIC_OPTIONS # dummy