xen/acpi: Move the xen_running_on_version_or_later function.

As on ia64 builds we get:
include/xen/interface/version.h: In function 'xen_running_on_version_or_later':
include/xen/interface/version.h:76: error: implicit declaration of function 'HYPERVISOR_xen_version'

We can later on make this function exportable if there are
modules using part of it. For right now the only two users are
built-in.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

include/xen/interface/version.h

@@ -63,22 +63,4 @@ struct xen_feature_info {
 /* arg == xen_domain_handle_t. */
 #define XENVER_guest_handle 8
 
-/* Declares the xen_domain() macros. */
-#include <xen/xen.h>
-
-/* Check if running on Xen version (major, minor) or later */
-static inline bool
-xen_running_on_version_or_later(unsigned int major, unsigned int minor)
-{
-	unsigned int version;
-
-	if (!xen_domain())
-		return false;
-
-	version = HYPERVISOR_xen_version(XENVER_version, NULL);
-	if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
-		((version >> 16) > major))
-		return true;
-	return false;
-}
 #endif /* __XEN_PUBLIC_VERSION_H__ */

include/xen/xen-ops.h

@@ -29,4 +29,5 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 			       unsigned long mfn, int nr,
 			       pgprot_t prot, unsigned domid);
 
+bool xen_running_on_version_or_later(unsigned int major, unsigned int minor);
 #endif /* INCLUDE_XEN_OPS_H */