fix hotn?, strcasecmp and timeval isn't defined error

by including arpa/inet.h, strings.h and sys/timer.h

Part of #935.

Change-Id: Ibac8d3a992457f2a7cc10f74b144e3ebe69976d8
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
(cherry picked from commit b9aa6cef43b338666a72bf6425fc88ed7602bce5)
Signed-off-by: Bruce A. Mah <bmah@es.net>

src/dscp.c

@@ -27,6 +27,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <strings.h>
 #include <stdlib.h>
 #include <inttypes.h>
 

src/iperf_tcp.c

@@ -29,6 +29,7 @@
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
+#include <arpa/inet.h>
 #include <sys/socket.h>
 #include <sys/types.h>
 #include <netinet/in.h>

src/iperf_udp.c

@@ -30,6 +30,7 @@
 #include <errno.h>
 #include <unistd.h>
 #include <assert.h>
+#include <arpa/inet.h>
 #include <sys/socket.h>
 #include <sys/types.h>
 #include <netinet/in.h>

src/net.c

@@ -29,6 +29,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <errno.h>
+#include <arpa/inet.h>
 #include <sys/socket.h>
 #include <sys/types.h>
 #include <netinet/in.h>

src/timer.h

@@ -31,6 +31,8 @@
 #define __TIMER_H
 
 #include <time.h>
+#include <sys/time.h>
+
 #include "iperf_time.h"
 
 /* TimerClientData is an opaque value that tags along with a timer.  The