coresight: Initialize arg in sparse friendly way

Sparse gets annoyed when this initializer is 0 but the first struct
member is a pointer. Just use { } to initialize instead so that sparse
is quiet.

Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200518180242.7916-19-mathieu.poirier@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>