Input: add a driver to support InvenSense mpu3050 gyroscope chip

This driver is registered as an input device. An IRQ is required in this
basic driver configuration.

Signed-off-by: Joseph Lai <joseph_lai@wistron.com>
[Cleaned up PM_RUNTIME defines]
Signed-off-by: Alan Cox <alan@linux.intel.com>
[dtor@mail.ru: consolidated PM methods, some code rearrangement]
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>