remoteproc: k3-m4: Don't assert reset in detach routine

remoteproc: k3-m4: Don't assert reset in detach routine

The rproc_detach() function invokes __rproc_detach() before
rproc_unprepare_device(). The __rproc_detach() function sets the
rproc->state to "RPROC_DETACHED".

However, the TI K3 M4 driver erroneously looks for "RPROC_ATTACHED"
state in its .unprepare ops to identify IPC-only mode; which leads to
resetting the rproc in detach routine.

Therefore, correct the IPC-only mode detection logic to look for
"RPROC_DETACHED" in k3_m4_rproc_unprepare() function.

Fixes: ebcf9008a895 ("remoteproc: k3-m4: Add a remoteproc driver for M4F subsystem")
Signed-off-by: Beleswar Padhi <b-padhi@ti.com>
Reviewed-by: Hari Nagalla <hnagalla@ti.com>
Reviewed-by: Martyn Welch <martyn.welch@collabora.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250513054510.3439842-5-b-padhi@ti.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>