coresight: Add config flag to enable branch broadcast

coresight: Add config flag to enable branch broadcast

When enabled, all taken branch addresses are output, even if the branch
was because of a direct branch instruction. This enables reconstruction
of the program flow without having access to the memory image of the
code being executed.

Use bit 8 for the config option which would be the correct bit for
programming ETMv3. Although branch broadcast can't be enabled on ETMv3
because it's not in the define ETM3X_SUPPORTED_OPTIONS, using the
correct bit might help prevent future collisions or allow it to be
enabled if needed.

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220511144601.2257870-2-james.clark@arm.com