HID: Move the hid-hyperv driver out of staging

The file  hid-hyperv.c implements a hid compliant mouse driver for use on a
Hyper-V based system. This driver is currently in the staging area and as part
of the effort to move this driver out of staging, I had posted the driver code
for community review a few weeks ago. This current patch addresses all the
review comments I have gotten to date. All the relevant patches have already
been submitted to the staging tree as well.

As per Greg's suggestion, this patch does not get rid of the code from
the staging area. Once the mouse driver lands under the hid directory,
we will cleanup the staging directory.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>