coresight: etm4x: Fix merge resolution for amba rework

This was non-trivial to get right because commits
c23bc382 ("coresight: etm4x: Refactor probing routine") and
5214b563 ("coresight: etm4x: Add support for sysreg only devices")
changed the code flow considerably. With this change the driver can be
built again.

Fixes: 0573d3fa

 ("Merge branch 'devel-stable' of git://git.armlinux.org.uk/~rmk/linux-arm into char-misc-next")
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210205130848.20009-1-uwe@kleine-koenig.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>