Binding for Qualcomm Atheros AR7xxx/AR9XXX SoC

Each device tree must specify a compatible value for the AR SoC
it uses in the compatible property of the root node. The compatible
value must be one of the following values:

- qca,ar7130
- qca,ar7141
- qca,ar7161
- qca,ar7240
- qca,ar7241
- qca,ar7242
- qca,ar9130
- qca,ar9132
- qca,ar9330
- qca,ar9331
- qca,ar9341
- qca,ar9342
- qca,ar9344
- qca,qca9556
- qca,qca9558
