rpmsg: glink: smem: Wrap driver context

The Glink SMEM driver allocates a struct device and hangs two
devres-allocated pipe objects thereon. To facilitate the move of
interrupt and mailbox handling to the driver, introduce a wrapper object
capturing the device, glink reference and remote processor id.

The type of the remoteproc reference is updated, as these are
specifically targeting the SMEM implementation.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230213155215.1237059-3-quic_bjorande@quicinc.com