add Kexec kernel option to menu, fix usage of shutdown -r in kexec

package/kexec-tools/patches/patch-kexec_kexec_c

@@ -0,0 +1,24 @@
+--- kexec-tools-2.0.2.orig/kexec/kexec.c	2010-07-29 06:19:59.000000000 +0200
++++ kexec-tools-2.0.2/kexec/kexec.c	2011-09-05 18:50:27.679232756 +0200
+@@ -796,17 +796,14 @@ int k_unload (unsigned long kexec_flags)
+ static int my_shutdown(void)
+ {
+ 	char *args[] = {
+-		"shutdown",
+-		"-r",
+-		"now",
++		"reboot",
++		"-f",
+ 		NULL
+ 	};
+ 
+-	execv("/sbin/shutdown", args);
+-	execv("/etc/shutdown", args);
+-	execv("/bin/shutdown", args);
++	execv("/sbin/reboot", args);
+ 
+-	perror("shutdown");
++	perror("reboot");
+ 	return -1;
+ }
+ 

target/linux/config/Config.in.misc

@@ -15,6 +15,12 @@ config ADK_KERNEL_RTC_INTF_DEV
 
 menu "Miscellaneous devices support"
 
+config ADK_KERNEL_KEXEC
+	prompt ".................................. Add KEXEC syscall"
+	boolean
+	help
+	  You need also kexec-tools to benefit from it.	
+
 config ADK_KERNEL_RTC_DRV_AT91SAM9
 	prompt ".................................. RTC support for AT91SAM9 (Fox G20)"
 	boolean