UPSTREAM: coresight: etb10: Handle errors enabling the device

Prepare the etb10 driver to return errors in enabling
the device.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

(Upstream commit 62563e84a8c9c682e07b8cce8678e583a24be504).

Bug: 140266694
Change-Id: I18bcfdccd016ce09b788a82dab854445f277209e
Signed-off-by: Yabin Cui <yabinc@google.com>