KVM: add kvm_arch_para_features stub to asm-generic/kvm_para.h

Needed by kvm_para_has_feature().
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

include/asm-generic/kvm_para.h

@@ -11,4 +11,9 @@ static inline bool kvm_check_and_clear_guest_paused(void)
 	return false;
 }
 
+static inline unsigned int kvm_arch_para_features(void)
+{
+	return 0;
+}
+
 #endif