coresight: etm4x: use module_param instead of module_param_named

coresight: etm4x: use module_param instead of module_param_named

Given that the user-exposed module parameter for 'boot_enable' matches
the variable that it sets, let's use module_param instead of
module_param_named.

Let's also use octal permissions (checkpatch recommends this) and
provide a module parameter description.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20190829202842.580-12-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>