samples: sensor: Fix logically dead code in bmg160 sample
samples: sensor: Fix logically dead code in bmg160 sample

Converts the bmg160 sample application to check the sensor device at
build time instead of runtime. This fixes a Coverity issue for logically
dead code introduced in commit 5832e588e3664cc0abb76847ac3a5e4d1954392d.

Fixes #35118
Coverity-CID: 235919

Signed-off-by: Maureen Helm <87a696db5547fa477bda9f9e0f00013c839c14d3@nxp.com>

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