Coresight: tpda/tpdm: remove incorrect __exit annotation

'remove' callbacks get called whenever a device is unbound from
the driver, which can get triggered from user space.

Putting it into the __exit section means that the function gets
dropped in for built-in drivers, as pointed out by this build
warning:

`tpda_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-tpda.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-tpda.o
`tpdm_remove' referenced in section `.data' of drivers/hwtracing/coresight/coresight-tpdm.o: defined in discarded section `.exit.text' of drivers/hwtracing/coresight/coresight-tpdm.o

Fixes: 5b791662 ("Coresight: Add TPDA link driver")
Fixes: b3c71626 ("Coresight: Add coresight TPDM source driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230126163530.3495413-1-arnd@kernel.org