KVM: export <asm/hyperv.h>

Needed by <asm/kvm_para.h>.

Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/include/asm/Kbuild

@@ -11,6 +11,7 @@ header-y += sigcontext32.h
 header-y += ucontext.h
 header-y += processor-flags.h
 header-y += hw_breakpoint.h
+header-y += hyperv.h
 
 unifdef-y += e820.h
 unifdef-y += ist.h