firmware: arm_scmi: Fix premature SCMI_XFER_FLAG_IS_RAW clearing in raw mode

The SCMI_XFER_FLAG_IS_RAW flag was being cleared prematurely in
scmi_xfer_raw_put() before the transfer completion was properly
acknowledged by the raw message handlers.

Move the clearing of SCMI_XFER_FLAG_IS_RAW and SCMI_XFER_FLAG_CHAN_SET
from scmi_xfer_raw_put() to __scmi_xfer_put() to ensure the flags remain
set throughout the entire raw message processing pipeline until the
transfer is returned to the free pool.

Fixes: 3095a3e2 ("firmware: arm_scmi: Add xfer helpers to provide raw access")
Suggested-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Artem Shimko <a.shimko.dev@gmail.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Message-Id: <20251008091057.1969260-1-a.shimko.dev@gmail.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>