Huawei continues its unexpected but rapid customer service, they have released a marshmallow update for the Mate7 Middle Eastern version. which can be installed on any Mate 7 device running official stock Lollipop 5.1 firmware.
Now Download C185B560 Firmware, extract the zip file & copy dload folder in your internal/sd card memory & force update using 3 button method (power + volume up + volume down). Remove any cable connected to the phone.
After Installation make sure you have build number MT7-TL10C185B560, if not please write in comments to fix it.