Do the following :
wget http://mirrors.kernel.org/ubuntu/pool/main/l/linux-firmware/linux-firmware_1.158_all.deb
sudo dpkg -i linux-firmware_1.158_all.deb
Then, install the backported modules and needed firmware :
sudo apt-get install build-essential linux-headers-$(uname -r) git
echo "options ath10k_core skip_otp=y" | sudo tee /etc/modprobe.d/ath10k_core.conf
wget https://www.kernel.org/pub/linux/kernel/projects/backports/stable/v4.4.2/backports-4.4.2-1.tar.gz
tar -zxvf backports-4.4.2-1.tar.gz
cd backport-4.4.2-1
make defconfig-wifi
make
sudo make install
git clone https://github.com/kvalo/ath10k-firmware.git
sudo cp -r ath10k-firmware/QCA9377 /lib/firmware/ath10k/
sudo cp /lib/firmware/ath10k/hw1.0/firmware-5.bin_WLAN.TF.1.0-00267-1 /lib/firmware/ath10k/QCA9377/hw1.0/firmware-5.bin
and reboot. That's it.
However, when a new kernel is installed through updates, the Wifi might fail.
Do the following :
cd backports-4.4.2-1
make clean
make defconfig-wifi
make
sudo make install