msm-fixes for v6.3-rc5

Two GPU fixes which were meant to be part of the previous pull request,
but I'd forgotten to fetch from gitlab after the MR was merged so that
git tag was applied to the wrong commit.

- kexec shutdown fix
- fix potential double free
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rob Clark <robdclark@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CAF6AEGskguoVsz2wqAK2k+f32LwcVY5JC6+e2RwLqZswz3RY2Q@mail.gmail.com