Download gphoto2 2.5.2:

cd /mnt/sda1
wget http://www.diy-wft.org/files/router-software/trunk/gphoto2_2.5.2-1_ar71xx.ipk
wget http://www.diy-wft.org/files/router-software/trunk/libgphoto2-drivers_2.5.2-1_ar71xx.ipk
wget http://www.diy-wft.org/files/router-software/trunk/libgphoto2_2.5.2-1_ar71xx.ipk

Install software ( order is important ):

opkg update
opkg install libgphoto2_2.5.2-1_ar71xx.ipk
opkg install gphoto2_2.5.2-1_ar71xx.ipk
opkg install libgphoto2-drivers_2.5.2-1_ar71xx.ipk

Alternate download site:

wget http://www.ibuyopenwrt.com/images/gphoto2_2.5.2-1_ar71xx.ipk
wget http://www.ibuyopenwrt.com/images/libgphoto2-drivers_2.5.2-1_ar71xx.ipk
wget http://www.ibuyopenwrt.com/images/libgphoto2_2.5.2-1_ar71xx.ipk