ARM: etm: Don't limit tracing to only non-secure code.

On some systems kernel code is considered secure, and this code
already limits tracing to the kernel text segment which results
in no trace data.

Change-Id: I098a0753e874859446d098e1ee209f67fc13cd5d
Signed-off-by: Arve Hjønnevåg <arve@android.com>