LU-18475 build: compatibility updates for kernel 6.13

LU-18475 build: compatibility updates for kernel 6.13

Linux v5.8-2483-gc0842fbc1b18
  random32: move the pseudo-random 32-bit definitions to prandom.h
Include prandom.h when available

Linux v6.13-rc1-2-gcdd30ebb1b9f
  module: Convert symbol namespace to string literal
__stringify macros used by MODULE_IMPORT_NS()

Linux v6.12-rc1-5-gfd15ba4cb00a
  ceph: Remove call to PagePrivate2()
PagePrivate2 removed, provide a replacement for older kernels.

Test-Parameters: trivial
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I6e1e43bad2fff967bbfce2e3df0f0f6ff251e413
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/57906
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>