port, dhcp: drop the called/done traces from the console and syslog

rtl837x_port.c prints "called" and "done" around mirroring, PVID, VLAN
and L2 setup, and dhcp.c around discover, request, start and stop. They
land on the console on every boot and config replay, and in the log
once syslog is running. The VLAN line keeps the VLAN, members and
tagged values, only without the function name in front.

On the KP_9000_6XHML_X2 this takes 359 bytes out of BANK1, 88 out of
BANK2 and 24 out of BANK3. BANK1 goes from 431 to 790 bytes free.

dhcp.c

@@ -157,7 +157,6 @@ void dhcp_addopt_server_id(void)
 
 void dhcp_send_discover(void)
 {
-	print_string("dhcp_send_discover called\n");
 	dhcp_prepare_request();
 
 	dhcp_state.opt_ptr = 0;
@@ -193,7 +192,6 @@ void dhcp_send_discover(void)
 
 void dhcp_send_request(void)
 {
-	print_string("dhcp_send_request called\n");
 	dhcp_prepare_request();
 
 	dhcp_state.opt_ptr = 0;
@@ -376,13 +374,11 @@ void dhcp_start(void) __banked
 	*tid++ = SFR_DATA_8;
 	*tid = SFR_DATA_0;
 	dhcp_state.state = DHCP_START;
-	print_string("dhcp_start done\n");
 }
 
 
 void dhcp_stop(void) __banked
 {
-	print_string("dhcp_stop called\n");
 	uip_udp_remove(dhcp_state.conn);
 	dhcp_state.state = DHCP_OFF;
 }