firmware: arm_scmi: Make raw debugfs entries non-seekable

SCMI raw debugfs entries are used to inject and snoop messages out of the
SCMI core and, as such, the underlying virtual files have no reason to
support seeking.

Modify the related file_operations descriptors to be non-seekable.

Fixes: 3c3d818a ("firmware: arm_scmi: Add core raw transmission support")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20240315140324.231830-1-cristian.marussi@arm.com


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>