samples: shields: lmp90100_evb: Fix nodelabel

Shield's nodelabels should now be in the form <device>_<shield_name>.
This occurrence was left out in the initial change.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

samples/shields/lmp90100_evb/rtd/app.overlay

@@ -4,6 +4,6 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-&lmp90100 {
+&lmp90100_lmp90100_evb {
 	rtd-current = <1000>;
 };