Add NUCLEO_F042K6 detection

Signed-off-by: Jerome COUTANT

Author: Jerome COUTANT

mbed_lstools/lstools_base.py

@@ -88,11 +88,11 @@ def __init__(self):
         "0775": "NUCLEO_F303K8",
         "0777": "NUCLEO_F446RE",
         "0780": "ST_PLACEHOLDER",
-        "0785": "ST_PLACEHOLDER",
+        "0785": "NUCLEO_F042K6",
         "0788": "DISCO_F469NI",
         "0790": "NUCLEO_L031K6",
         "0791": "NUCLEO_F031K6",
-        "0795": "DISCO_F429ZI",	
+        "0795": "DISCO_F429ZI",
         "0799": "ST_PLACEHOLDER",
         "0805": "DISCO_L053C8",
         "0810": "DISCO_F334C8",