revert dma-mapping and vmap API abuse in qcom_q6v5_mss

[Christoph Hellwig]

Hi all,

this series reverts a completely broken commit to qcom_q6v5_mss the
abuses the dma-mapping and vmap APIs in multiple, and mostly clearly
documented ways, and then adds a patch to document and reject the
so far undocumented API abuse.

Diffstat:
 drivers/remoteproc/qcom_q6v5_mss.c |   38 +++++--------------------------------
 mm/vmalloc.c                       |    3 ++
 2 files changed, 9 insertions(+), 32 deletions(-)