misc: fastrpc: Add support to secure memory map

This patch repurposes the attribute field in struct fastrpc_invoke_args
to add attributes to invoke request, for example to setup a secure memory
map for dsp. Secure memory is assigned fastrpc Virtual Machine IDs.

Signed-off-by: Vamsi Krishna Gattupalli <quic_vgattupa@quicinc.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>