remoteproc: core: Move validate before device add

We can validate whether the remoteproc is correctly setup before
making the cdev_add and device_add calls. This saves us the
trouble of cleaning up later on.

Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1623723671-5517-3-git-send-email-sidgup@codeaurora.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>