tests: message_capture: do not exclude intel_adsp_cavs15
tests: message_capture: do not exclude intel_adsp_cavs15

No reason to exclude this platform, we only have been using wrong
logging defaults (which was set in the soc) and not printing log
messages which is required by the test.

Signed-off-by: Anas Nashif <0d9952ec84ac43c159f6b7e7ed99a9080c00dd6e@intel.com>

zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr