fix: mm: move kvmalloc-related functions to slab.h (v5.16)

fix: mm: move kvmalloc-related functions to slab.h (v5.16)

See upstream commit :

  commit 8587ca6f34152ea650bad4b2db68456601159024
  Author: Matthew Wilcox (Oracle) <willy@infradead.org>
  Date:   Fri Nov 5 13:35:07 2021 -0700

    mm: move kvmalloc-related functions to slab.h

    Not all files in the kernel should include mm.h.  Migrating callers from
    kmalloc to kvmalloc is easier if the kvmalloc functions are in slab.h.

    [akpm@linux-foundation.org: move the new kvrealloc() also]
    [akpm@linux-foundation.org: drivers/hwmon/occ/p9_sbe.c needs slab.h]

Link: https://lkml.kernel.org/r/20210622215757.3525604-1-willy@infradead.org
Change-Id: I84e885ffbd1e2ff551a4738950e0c9462551b853
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>