rpmsg: core: Drop dev_pm_domain_detach() call

rpmsg: core: Drop dev_pm_domain_detach() call

Starting with commit f99508074e78 ("PM: domains: Detach on
device_unbind_cleanup()"), there is no longer a need to call
dev_pm_domain_detach() in the bus remove function. The
device_unbind_cleanup() function now handles this to avoid
invoking devres cleanup handlers while the PM domain is
powered off, which could otherwise lead to failures as
described in the above-mentioned commit.

Drop the explicit dev_pm_domain_detach() call and rely instead
on the flags passed to dev_pm_domain_attach() to power off the
domain.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20250827101352.927542-1-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>