misc: Add APQ8084 Docking Station driver

This driver is used to coordinate the GPIOs used to power
up and reset the USB hub and ethernet ports on the QTI
APQ8084 Docking Station.

Change-Id: Ie1baf294396086aaaa342025349aa146bef8d0b5
Signed-off-by: Jack Pham <jackp@codeaurora.org>