samples: net: socket: Add "socket" tag to sample.yaml's

So it was easy to run all socket tests without remembering
the exact path(s).

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>

samples/net/sockets/big_http_download/sample.yaml

@@ -7,4 +7,4 @@ tests:
     harness: net
     min_ram: 32
     min_flash: 128
-    tags: net
+    tags: net socket

samples/net/sockets/coap_client/sample.yaml

@@ -4,5 +4,5 @@ sample:
 tests:
   test:
     harness: net
-    tags: net
+    tags: net socket
     platform_whitelist: qemu_x86

samples/net/sockets/coap_server/sample.yaml

@@ -4,5 +4,5 @@ sample:
 tests:
   test:
     harness: net
-    tags: net
+    tags: net socket
     platform_whitelist: qemu_x86

samples/net/sockets/dumb_http_server/sample.yaml

@@ -6,4 +6,4 @@ tests:
     platform_exclude: esp32 qemu_x86_64 # No newlib
     harness: net
     min_ram: 32
-    tags: net
+    tags: net socket

samples/net/sockets/echo/sample.yaml

@@ -5,4 +5,4 @@ tests:
   test:
     harness: net
     depends_on: netif
-    tags: net
+    tags: net socket

samples/net/sockets/echo_async/sample.yaml

@@ -6,4 +6,4 @@ tests:
   test:
     harness: net
     platform_whitelist: qemu_x86
-    tags: net
+    tags: net socket

samples/net/sockets/echo_client/sample.yaml

@@ -8,5 +8,5 @@ sample:
   name: Socket Echo Client
 tests:
   test:
-    tags: net
+    tags: net socket
     min_flash: 140

samples/net/sockets/echo_server/sample.yaml

@@ -8,5 +8,5 @@ sample:
   name: Socket Echo Server
 tests:
   test:
-    tags: net
+    tags: net socket
     min_flash: 140

samples/net/sockets/http_get/sample.yaml

@@ -6,4 +6,4 @@ tests:
     platform_exclude: esp32 qemu_x86_64 # No newlib
     harness: net
     min_ram: 32
-    tags: net
+    tags: net socket