log: backend: net: Remove Posix dependency

The network backend needs nothing from Posix so remove the
dependency.

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>

Author: jukkar

subsys/logging/backends/Kconfig.net

@@ -6,7 +6,6 @@
 config LOG_BACKEND_NET
 	bool "Networking backend"
 	depends on NETWORKING && (NET_UDP || NET_TCP) && NET_SOCKETS && !LOG_MODE_IMMEDIATE
-	depends on POSIX_C_LANG_SUPPORT_R
 	help
 	  Send syslog messages to network server.
 	  See RFC 5424 (syslog protocol) and RFC 5426 (syslog over UDP) and