qrtr: add MODULE_ALIAS macro to smd

Added MODULE_ALIAS("rpmsg:IPCRTR") to ensure qrtr-smd and qrtr will load
when IPCRTR channel is detected.

Signed-off-by: Ramon Fried <rfried@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>