reboot payload for mipsbe

This is the big endian version of the MIPS reboot payload (https://github.com/rapid7/metasploit-framework/pull/3041)

Original source of this payload: http://www.shell-storm.org/shellcode/files/shellcode-795.php

[1.9.3-p125@msf] (mipsbe_reboot_payload) root@msf-fu:~/msf-git/metasploit-framework#
#./msfpayload linux/mipsbe/reboot X > /firmware_stuff/learning_mips/mipsbe_reboot.elf
Created by msfpayload (http://www.metasploit.com).
Payload: linux/mipsbe/reboot
 Length: 32
Options: {}
[1.9.3-p125@msf] (mipsbe_reboot_payload) root@msf-fu:~/msf-git/metasploit-framework#
#file /firmware_stuff/learning_mips/mipsbe_reboot.elf
/firmware_stuff/learning_mips/mipsbe_reboot.elf: ELF 32-bit MSB executable, MIPS, MIPS-I version 1 (SYSV), statically linked, corrupted section header size