rename _end to __bss_end__

Currently, _end is used for end of BSS section.  We want _end to mean
end of u-boot image, so we rename _end to __bss_end__ first.

Signed-off-by: Po-Yu Chuang <ratbert@faraday-tech.com>
diff --git a/arch/arm/cpu/arm920t/ep93xx/u-boot.lds b/arch/arm/cpu/arm920t/ep93xx/u-boot.lds
index 5bfcb02..4cc82a5 100644
--- a/arch/arm/cpu/arm920t/ep93xx/u-boot.lds
+++ b/arch/arm/cpu/arm920t/ep93xx/u-boot.lds
@@ -55,5 +55,5 @@
 	. = ALIGN(4);
 	__bss_start = .;
 	.bss : { *(.bss) }
-	_end = .;
+	__bss_end__ = .;
 }
diff --git a/arch/arm/cpu/arm920t/start.S b/arch/arm/cpu/arm920t/start.S
index 2fc0abc..6db61c2 100644
--- a/arch/arm/cpu/arm920t/start.S
+++ b/arch/arm/cpu/arm920t/start.S
@@ -87,7 +87,7 @@
 
 .globl _bss_end_ofs
 _bss_end_ofs:
-	.word _end - _start
+	.word __bss_end__ - _start
 
 #ifdef CONFIG_USE_IRQ
 /* IRQ stack memory (calculated at run-time) */
diff --git a/arch/arm/cpu/arm920t/u-boot.lds b/arch/arm/cpu/arm920t/u-boot.lds
index a6f8b56..d6dc21c 100644
--- a/arch/arm/cpu/arm920t/u-boot.lds
+++ b/arch/arm/cpu/arm920t/u-boot.lds
@@ -75,7 +75,7 @@
 		__bss_start = .;
 		*(.bss)
 		 . = ALIGN(4);
-		_end = .;
+		__bss_end__ = .;
 	}
 
 	/DISCARD/ : { *(.dynstr*) }