x86, HyperV: fix up the license to mshyperv.c

This should have been GPLv2 only, we cut and pasted from the wrong file
originally, sorry.

Also removed some unneeded boilerplate license code, we all know where
to find the GPLv2, and that there's no warranty as that is implicit from
the license.

Cc: Ky Srinivasan <ksrinivasan@novell.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
LKML-Reference: <20100507235541.GA15448@kroah.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>