xen: create xen_create/destroy_contiguous_region() stubs for PVHVM only builds

xen_create_contiguous_region()/xen_create_contiguous_region() are PV-only,
they both contain xen_feature(XENFEAT_auto_translated_physmap) check and
bail in the very beginning.

Signed-off-by: Vitaly Kuznetsov <[e-mail]>
Reviewed-by: Juergen Gross <[e-mail]>
Signed-off-by: Juergen Gross <[e-mail]>

include/xen/xen-ops.h

···
 int xen_setup_shutdown_event(void);
 
 extern unsigned long *xen_contiguous_bitmap;
+
+#ifdef CONFIG_XEN_PV
 int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
 				unsigned int address_bits,
 				dma_addr_t *dma_handle);
 
 void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order);
+#else
+static inline int xen_create_contiguous_region(phys_addr_t pstart,
+					       unsigned int order,
+					       unsigned int address_bits,
+					       dma_addr_t *dma_handle)
+{
+	return 0;
+}
+
+static inline void xen_destroy_contiguous_region(phys_addr_t pstart,
+						 unsigned int order) { }
+#endif
 
 struct vm_area_struct;