Staging: hv: Cleanup vmalloc calls

The subject says it all. There is no need to
specify different page protection bits based
on the architecture.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>