CHROMIUM: WAR: misc: fastrpc: do not release memory if in use by the DSP

the processor must wait for the DSP release operation to terminate
before proceeding to release the memory mapped to the DSP.

BUG=b:137202421
TEST=Run label_image in loop

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: Abhinav Asati <asatiabhi@codeaurora.org>
(cherry picked from commit 95e471b433761cd873c310b99c77c8d89f452e00
https://github.com/ldts/qualcomm-lt-kernel/commits/chromiumos-4.14-iommu-mmap-gw-rebased-for-next

)
Change-Id: I867200ab1d91e7ab9b3a100c7f9806cef5ffe95a
Signed-off-by: Vamsi Singamsetty <vamssi@codeaurora.org>