ideapad: uninitialized data in ideapad_acpi_add()

We only initialize the high bits of "cfg".  It probably doesn't cause
a problem given that this is platform specific code and doesn't have to
worry about endianness etc.  But it's sort of messy.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>