hv: Add hyperv.h to uapi headers

This patch adds the hyperv.h header to the uapi folder, and adds it to the Kbuild file.
Doing this enables compiling userspace Hyper-V tools using the installed headers.

Version 2: Split UAPI parts into new header, instead of duplicating.

Signed-off-by: Bjarke Istrup Pedersen <gurligebis@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
index 3ce25b5..6929571 100644
--- a/include/uapi/linux/Kbuild
+++ b/include/uapi/linux/Kbuild
@@ -139,6 +139,7 @@
 header-y += hiddev.h
 header-y += hidraw.h
 header-y += hpet.h
+header-y += hyperv.h
 header-y += hysdn_if.h
 header-y += i2c-dev.h
 header-y += i2c.h