Initialize UAPI structs copied to user space

To not leak any information from kernel space when IOCTL calls copy data
from kernel space to user space, the source struct in the IOCTL calls is
now initialized.

Change-Id: I0825e82ccdb51ced747e160dd7385fa1ed227eaf
Signed-off-by: Mikael Olsson <mikael.olsson@arm.com>