HID: microsoft: Add Surface Power Cover

Adding support for the Microsoft Surface Pro Power Cover.

Signed-off-by: Raimund Roth <raimundmroth@gmail.gom>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --cc drivers/hid/hid-core.c
Simple merge

diff --cc drivers/hid/hid-ids.h
Simple merge

diff --cc drivers/hid/hid-microsoft.c
Simple merge

diff --cc drivers/hid/usbhid/hid-quirks.c
Simple merge