Cordio: Fix default COC parameters.

The stack doesn't cope with zero COC client or channel on IAR.

Author: pan-

features/FEATURE_BLE/targets/TARGET_CORDIO/mbed_lib.json

@@ -24,12 +24,12 @@
         },
         "max-l2cap-channels": {
             "help": "Maximum number of connection oriented channels",
-            "value": 0,
+            "value": 1,
             "macro_name": "L2C_COC_CHAN_MAX"
         },
         "max-l2cap-clients": {
             "help": "Maximum number of connection oriented channel registered clients",
-            "value": 0,
+            "value": 1,
             "macro_name": "L2C_COC_REG_MAX"
         },
         "max-att-writes": {