remoteproc: wkup_m3: Set sysfs_read_only flag

The Wakeup M3 remote processor is controlled by the wkup_m3_ipc
client driver, so set the newly introduced 'sysfs_read_only' flag
to not allow any overriding of the remoteproc firmware, state,
recovery, or coredump from userspace.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
Link: https://lore.kernel.org/r/20220216081224.9956-3-p-mohan@ti.com


Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>