Add support for Chrome OS firmware signals

Martyn Welch
2015-12-01T19:13:10Z

Some Chromebooks have gpio attached to signals used to cause the firmware
to enter alternative modes of operation and/or control other device
characteristics (such as write protection on flash devices). This patch
adds a driver that exposes a read-only interface to allow these signals to
be read from user space.

In addition this patch series provides the required bindings for this to the
peach-pi Chromebook.