unify version_string

This patch removes the architecture specific implementation of
version_string where possible. Some architectures use a special place
and therefore we provide U_BOOT_VERSION_STRING definition and a common
weak symbol version_string.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
CC: Mike Frysinger <vapier@gentoo.org>
CC: Peter Pan <pppeterpppan@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/powerpc/cpu/mpc5xxx/start.S b/arch/powerpc/cpu/mpc5xxx/start.S
index 192aa50..51cc4e2 100644
--- a/arch/powerpc/cpu/mpc5xxx/start.S
+++ b/arch/powerpc/cpu/mpc5xxx/start.S
@@ -28,7 +28,6 @@
 #include <asm-offsets.h>
 #include <config.h>
 #include <mpc5xxx.h>
-#include <timestamp.h>
 #include <version.h>
 
 #define CONFIG_MPC5xxx 1	/* needed for Linux kernel header files */
@@ -41,10 +40,6 @@
 #include <asm/mmu.h>
 #include <asm/u-boot.h>
 
-#ifndef  CONFIG_IDENT_STRING
-#define  CONFIG_IDENT_STRING ""
-#endif
-
 /* We don't want the  MMU yet.
 */
 #undef	MSR_KERNEL
@@ -80,9 +75,7 @@
 	.data
 	.globl	version_string
 version_string:
-	.ascii U_BOOT_VERSION
-	.ascii " (", U_BOOT_DATE, " - ", U_BOOT_TIME, ")"
-	.ascii CONFIG_IDENT_STRING, "\0"
+	.ascii U_BOOT_VERSION_STRING, "\0"
 
 /*
  * Exception vectors