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/ppc4xx/start.S b/arch/powerpc/cpu/ppc4xx/start.S
index b43e22c..3b0e364 100644
--- a/arch/powerpc/cpu/ppc4xx/start.S
+++ b/arch/powerpc/cpu/ppc4xx/start.S
@@ -68,7 +68,6 @@
 #include <asm-offsets.h>
 #include <config.h>
 #include <asm/ppc4xx.h>
-#include <timestamp.h>
 #include <version.h>
 
 #define _LINUX_CONFIG_H 1	/* avoid reading Linux autoconf.h file	*/
@@ -80,10 +79,6 @@
 #include <asm/mmu.h>
 #include <asm/ppc4xx-isram.h>
 
-#ifndef	 CONFIG_IDENT_STRING
-#define	 CONFIG_IDENT_STRING ""
-#endif
-
 #ifdef CONFIG_SYS_INIT_DCACHE_CS
 # if (CONFIG_SYS_INIT_DCACHE_CS == 0)
 #  define PBxAP PB1AP
@@ -549,9 +544,7 @@
 	.long	0x27051956		/* U-Boot Magic Number			*/
 	.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"
 
 	. = EXC_OFF_SYS_RESET
 	.globl	_start_of_vectors