coresight: trbe: Remove redundant disable call

coresight: trbe: Remove redundant disable call

trbe_drain_and_disable_local() just clears TRBLIMITR and drains.
TRBLIMITR is already cleared on the next line after this call, so
replace it with only drain. This is so we can make a kvm call that has a
preempt enabled warning from set_trbe_disabled() in the next commit,
where trbe_reset_local() is called from a preemptible hotplug path.

Signed-off-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250106142446.628923-5-james.clark@linaro.org
Signed-off-by: Marc Zyngier <maz@kernel.org>