include/linux/memory.h: drop fields 'hw' and 'phys_callback' from struct memory_block

memory_block structure elements 'hw' and 'phys_callback' are not getting
used.  This was originally added with commit 3947be19 ("[PATCH]
memory hotplug: sysfs and add/remove functions") but never seem to have
been used.  Just drop them now.

Link: http://lkml.kernel.org/r/1576728650-13867-1-git-send-email-anshuman.khandual@arm.comSigned-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/memory.h

@@ -29,8 +29,6 @@ struct memory_block {
 	int section_count;		/* serialized by mem_sysfs_mutex */
 	int online_type;		/* for passing data to online routine */
 	int phys_device;		/* to which fru does this belong? */
-	void *hw;			/* optional pointer to fw/hw data */
-	int (*phys_callback)(struct memory_block *);
 	struct device dev;
 	int nid;			/* NID for this memory block */
 };