CODEOWNERS: adding code-owner for arch/arm test suite

Assigning a code-owner for all tests under tests/arch/arm.

Signed-off-by: Ioannis Glaropoulos <[email protected]>

Author: ioannisg

CODEOWNERS

@@ -354,6 +354,7 @@
 /subsys/testsuite/                        @nashif
 /subsys/usb/                              @jfischer-phytec-iot @finikorg
 /tests/                                   @nashif
+/tests/arch/arm/                          @ioannisg
 /tests/boards/native_posix/               @aescolar
 /tests/boards/intel_s1000_crb/            @dcpleung @sathishkuttan
 /tests/bluetooth/                         @joerchan @jhedberg @Vudentz