remoteproc: Add device-managed variants of rproc_alloc/rproc_add

remoteproc: Add device-managed variants of rproc_alloc/rproc_add

Add API functions devm_rproc_alloc() and devm_rproc_add(), which behave
like rproc_alloc() and rproc_add() respectively, but register their
respective cleanup function to be called on driver detach.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20200417170040.174319-2-paul@crapouillou.net
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>