soc: qcom: mem-buf: Add support for consumers to import dma-bufs

Supplier virtual machines (VMs) support exporting dma-bufs to
a consumer VM. However, consumers do not support importing dma-bufs
into their VMs, so add an IOCTL command to import a dma-buf into
a consumer VM.

The client must provide a memory parcel handle that corresponds to a
dma-buf that has been shared with the consumer VM, as well as an
access control list that is used for validating the access control
rules for the buffer. Upon success, the client is given a dma-buf
fd, which they can use to map the buffer and access it from both
the CPU, and peripherals.

Change-Id: I548e004e73543421b932430fbd9f84ad76658ef8
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>