rpmsg: glink: Move irq and mbox handling to transports

Not all GLINK transports uses an interrupt and a mailbox instance. The
interrupt for RPM needs to be IRQF_NOSUSPEND, while it seems reasonable
for the SMEM interrupt to use irq_set_wake. The glink struct device is
constructed in the SMEM and RPM drivers but torn down in the core
driver.

Move the interrupt and kick handling into the SMEM and RPM driver, to
improve this and facilitate further improvements.

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/20230213155215.1237059-5-quic_bjorande@quicinc.com