[RAS] PSTORE code changes

[quanxian]

[Feature Description]

PSTORE codes has big change in mainline kernel v5.8.7 release version, which also supported saving system crash info to block device.

Fixes and new features for pstore.

      This is a pretty big set of changes (relative to past pstore pulls),
      but it has been in -next for a while. The biggest change here is the
      ability to support a block device as a pstore backend, which has been
      desired for a while. A lot of additional fixes and refactorings are
      also included, mostly in support of the new features.

Related informaiton from Linux kernel mainline

commit 829f3b9401fe7cc3c1f3642bb2520751a42a87df
Merge: 81e8c10 78c0824
Author: Linus Torvalds <email address hidden>
Date: Mon Jun 1 12:07:34 2020 -0700

    Merge tag 'pstore-v5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

    Pull pstore updates from Kees Cook:
     "Fixes and new features for pstore.

      This is a pretty big set of changes (relative to past pstore pulls),
      but it has been in -next for a while. The biggest change here is the
      ability to support a block device as a pstore backend, which has been
      desired for a while. A lot of additional fixes and refactorings are
      also included, mostly in support of the new features.

       - refactor pstore locking for safer module unloading (Kees Cook)

       - remove orphaned records from pstorefs when backend unloaded (Kees
         Cook)

       - refactor dump_oops parameter into max_reason (Pavel Tatashin)

       - introduce pstore/zone for common code for contiguous storage
         (WeiXiong Liao)

       - introduce pstore/blk for block device backend (WeiXiong Liao)

       - introduce mtd backend (WeiXiong Liao)"

Target Kernel: 5.8
Target Release: 20.10

[HW/SW Information]
Platform independent

[Business Justification]
Function enabling