sh: Fix build in start.S

By commit 6d8962e8,
label of _start was not usable in start.S and build fail.
This change label from  _start to _sh_start.

----
arch/sh/cpu/sh4/libsh4.o: In function `_start':
(.text+0x204): multiple definition of `_start'
arch/sh/cpu/sh4/start.o:(.text+0x0): first defined here
----

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>

arch/sh/cpu/sh2/start.S

@@ -26,7 +26,7 @@
 	.align	2
 
 	.global	_start
-_start:
+_sh_start:
 	.long 0x00000010	/* Ppower ON reset PC*/
 	.long 0x00000000
 	.long 0x00000010	/* Manual reset PC */
@@ -39,7 +39,7 @@ _init:
 	nop
 1:	sts	pr, r5
 	mov.l	._reloc_dst, r4
-	add	#(_start-1b), r5
+	add	#(_sh_start-1b), r5
 	mov.l	._reloc_dst_end, r6
 
 2:	mov.l	@r5+, r1
@@ -74,6 +74,6 @@ loop:
 ._reloc_dst_end:	.long	reloc_dst_end
 ._bss_start:		.long	bss_start
 ._bss_end:		.long	bss_end
-._gd_init:		.long	(_start - GENERATED_GBL_DATA_SIZE)
-._stack_init:	.long	(_start - GENERATED_GBL_DATA_SIZE - CONFIG_SYS_MALLOC_LEN - 16)
+._gd_init:		.long	(_sh_start - GENERATED_GBL_DATA_SIZE)
+._stack_init:	.long	(_sh_start - GENERATED_GBL_DATA_SIZE - CONFIG_SYS_MALLOC_LEN - 16)
 ._sh_generic_init:	.long	sh_generic_init

arch/sh/cpu/sh3/start.S

@@ -29,7 +29,7 @@
 	.align	2
 
 	.global	_start
-_start:
+_sh_start:
 	mov.l	._lowlevel_init, r0
 100:	bsrf	r0
 	nop
@@ -38,7 +38,7 @@ _start:
 	nop
 1:	sts	pr, r5
 	mov.l	._reloc_dst, r4
-	add	#(_start-1b), r5
+	add	#(_sh_start-1b), r5
 	mov.l	._reloc_dst_end, r6
 
 2:	mov.l	@r5+, r1
@@ -73,6 +73,6 @@ loop:
 ._reloc_dst_end:	.long	reloc_dst_end
 ._bss_start:		.long	bss_start
 ._bss_end:		.long	bss_end
-._gd_init:		.long	(_start - GENERATED_GBL_DATA_SIZE)
-._stack_init:	.long	(_start - GENERATED_GBL_DATA_SIZE - CONFIG_SYS_MALLOC_LEN - 16)
+._gd_init:		.long	(_sh_start - GENERATED_GBL_DATA_SIZE)
+._stack_init:	.long	(_sh_start - GENERATED_GBL_DATA_SIZE - CONFIG_SYS_MALLOC_LEN - 16)
 ._sh_generic_init:	.long	sh_generic_init

arch/sh/cpu/sh4/start.S

 /*
- * (C) Copyright 2007
+ * (C) Copyright 2007, 2010
  * Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
  *
  * This program is free software; you can redistribute it and/or
@@ -26,7 +26,7 @@
 	.align	2
 
 	.global	_start
-_start:
+_sh_start:
 	mov.l	._lowlevel_init, r0
 100:	bsrf	r0
 	nop
@@ -35,7 +35,7 @@ _start:
 	nop
 1:	sts	pr, r5
 	mov.l	._reloc_dst, r4
-	add	#(_start-1b), r5
+	add	#(_sh_start-1b), r5
 	mov.l	._reloc_dst_end, r6
 
 2:	mov.l	@r5+, r1
@@ -70,6 +70,6 @@ loop:
 ._reloc_dst_end:	.long	reloc_dst_end
 ._bss_start:		.long	bss_start
 ._bss_end:		.long	bss_end
-._gd_init:		.long	(_start - GENERATED_GBL_DATA_SIZE)
-._stack_init:		.long	(_start - GENERATED_GBL_DATA_SIZE - CONFIG_SYS_MALLOC_LEN - 16)
+._gd_init:		.long	(_sh_start - GENERATED_GBL_DATA_SIZE)
+._stack_init:		.long	(_sh_start - GENERATED_GBL_DATA_SIZE - CONFIG_SYS_MALLOC_LEN - 16)
 ._sh_generic_init:	.long	sh_generic_init