misc: fastrpc: add support for FASTRPC_IOCTL_MEM_MAP/UNMAP

Add support for IOCTL requests to map and unmap on DSP based on map
flags.

Signed-off-by: Jeya R <jeyr@codeaurora.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220214161002.6831-3-srinivas.kandagatla@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>