Staging: hv: remove UINT8 and INT8 typedefs

The UINT8 and INT8 typedefs are now removed from the Hyper-V driver
code.

Had to include <linux/kernel.h> in a few places to get the
build to work properly as well.

Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>