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/arch/arm/cpu/arm1176/start.S b/arch/arm/cpu/arm1176/start.S
index 1402924..5a15365 100644
--- a/arch/arm/cpu/arm1176/start.S
+++ b/arch/arm/cpu/arm1176/start.S
@@ -88,7 +88,7 @@
 
 	/* Prepare to disable the MMU */
 	adr	r2, mmu_disable_phys
-	sub	r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - CONFIG_SYS_TEXT_BASE)
+	sub	r2, r2, #(CONFIG_SYS_PHY_UBOOT_BASE - CONFIG_TEXT_BASE)
 	b	mmu_disable
 
 	.align 5