This patch ensures that a GPIO driver is loaded and set up before the
button driver can bind to the MSHW0040 device. Without this the driver
may not bind to the MSHW0040 device at all.
Adds a driver for the Surface platform Integration Device (SID) of the
Surface Book 2. This allows for setting the performance-mode, which can
be used to choose between performance-optimized vs. quiet operation.
The performance-mode can be set via the perf_mode sysfs attribute on the
corresponding device (MSHW0107).
