Sync buffalo.sh with the one in ramips/mt7621 to improve handling of the
TRX magic numbers of Buffalo WSR devices and switching sysupgrade method
between buffalo_upgrade_ubinized() and nand_do_upgrade().
Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/17408
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>