misc: fastrpc: make sure memory read and writes are visible

misc: fastrpc: make sure memory read and writes are visible

[ Upstream commit 415a0729bd1225f0ffbc0ba82888dd65772554f7 ]

dma_alloc_coherent buffers could have writes queued in store buffers so
commit them before sending buffer to DSP using correct dma barriers.
Same with vice-versa.

Fixes: c68cfb718c8f ("misc: fastrpc: Add support for context Invoke method")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>