Manual FW upgrade

Manual update procedure mentioned here Manual firmware upgrade says:

Copy the file in the root folder of the sd card.

ROOT FOLDER OF SD CARD is not `/root`

Working “remote” procedure:

Download latest firmware. On my PC I'm using simple wget command:

wget https://github.com/roleoroleo/yi-hack-Allwinner-v2/releases/download/0.3.2/y21ga_0.3.2.tgz

Upload downloaded firmware to camera's SD card root/tmp/sd but with changed version number to `x` letters:
```
scp y21ga_0.3.2.tgz scp://root@192.168.177.187//tmp/sd/y21ga_x.x.x.tgz
```
Press Upgrade Firmware button