samples: i2c_lsm9ds0: change hard-coded device name

Instead of using a hard-coded device name in the device binding
call, use the config name defined by the driver Kconfig as that
is safer and the app does not need to change when the device name
is changed.

Jira: ZEP-1764

Change-Id: I99efc4bcae0d1acae70f7820f69dfffbe17510a6
Signed-off-by: Kuo-Lang Tseng <kuo-lang.tseng@intel.com>