remoteproc: Move rproc_delete_debug_dir() to rproc_del()

The "remoteproc{0,1...}" sysfs entries are added in
rproc_add() and deleted in rproc_type_release() instead of
in rproc_del(). That leaves these lingering entries sticking
around after we return from rproc_del(). Move the
rproc_delete_debug_dir() to rproc_del() to fix this.

Signed-off-by: Sarangdhar Joshi <spjoshi@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>