[spinel] add capability definitions for FTD, MTD, RADIO configuration (#3357)

This commit adds new spinel capability definitions to specify the
FTD, MTD or RADIO build configurations. Depending on the OpenThread
build configurations the corresponding capability is included in
`SPINEL_PROP_CAPS` list.

src/ncp/ncp_base.cpp

@@ -1724,6 +1724,14 @@ template <> otError NcpBase::HandlePropertyGet<SPINEL_PROP_CAPS>(void)
     SuccessOrExit(error = mEncoder.WriteUintPacked(SPINEL_CAP_MCU_POWER_STATE));
 #endif
 
+#if OPENTHREAD_FTD
+    SuccessOrExit(error = mEncoder.WriteUintPacked(SPINEL_CAP_CONFIG_FTD));
+#elif OPENTHREAD_MTD
+    SuccessOrExit(error = mEncoder.WriteUintPacked(SPINEL_CAP_CONFIG_MTD));
+#elif OPENTHREAD_RADIO
+    SuccessOrExit(error = mEncoder.WriteUintPacked(SPINEL_CAP_CONFIG_RADIO));
+#endif
+
 #if OPENTHREAD_RADIO || OPENTHREAD_ENABLE_RAW_LINK_API
     SuccessOrExit(error = mEncoder.WriteUintPacked(SPINEL_CAP_MAC_RAW));
 #endif

src/ncp/spinel.c

@@ -2411,6 +2411,18 @@ const char *spinel_capability_to_cstr(unsigned int capability)
         ret = "802_15_4_868MHZ_ASK";
         break;
 
+    case SPINEL_CAP_CONFIG_FTD:
+        ret = "CONFIG_FTD";
+        break;
+
+    case SPINEL_CAP_CONFIG_MTD:
+        ret = "CONFIG_MTD";
+        break;
+
+    case SPINEL_CAP_CONFIG_RADIO:
+        ret = "CONFIG_RADIO";
+        break;
+
     case SPINEL_CAP_ROLE_ROUTER:
         ret = "ROLE_ROUTER";
         break;

src/ncp/spinel.h

@@ -740,6 +740,12 @@ enum
     SPINEL_CAP_802_15_4_868MHZ_ASK    = (SPINEL_CAP_802_15_4__BEGIN + 14),
     SPINEL_CAP_802_15_4__END          = 32,
 
+    SPINEL_CAP_CONFIG__BEGIN = 32,
+    SPINEL_CAP_CONFIG_FTD    = (SPINEL_CAP_CONFIG__BEGIN + 0),
+    SPINEL_CAP_CONFIG_MTD    = (SPINEL_CAP_CONFIG__BEGIN + 1),
+    SPINEL_CAP_CONFIG_RADIO  = (SPINEL_CAP_CONFIG__BEGIN + 2),
+    SPINEL_CAP_CONFIG__END   = 40,
+
     SPINEL_CAP_ROLE__BEGIN = 48,
     SPINEL_CAP_ROLE_ROUTER = (SPINEL_CAP_ROLE__BEGIN + 0),
     SPINEL_CAP_ROLE_SLEEPY = (SPINEL_CAP_ROLE__BEGIN + 1),