coresight: Mark some functions static

coresight: Mark some functions static

These functions aren't used outside the file they're in. Mark them
static to indicate as such and silence tools like sparse.

Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
[Dropped changes in coresight-cti.c and coresight-etb10.c]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200518180242.7916-17-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>