Add enum p4io_roundplug_type for clarity

src/main/p4io/cmd.h

@@ -5,7 +5,7 @@
 
 #define P4IO_SOF 0xAA
 
-enum p4ioemu_p4io_command {
+enum p4io_command {
     P4IO_CMD_INIT = 0x00,
     P4IO_CMD_GET_DEVICE_INFO = 0x01,
     P4IO_CMD_SET_PORTOUT = 0x12,
@@ -21,6 +21,11 @@ enum p4ioemu_p4io_command {
     P4IO_CMD_DALLAS_READ_MEM = 0x41
 };
 
+enum p4io_roundplug_type {
+    P4IO_ROUNDPLUG_BLACK = 0,
+    P4IO_ROUNDPLUG_WHITE = 1,
+};
+
 #define P4IO_CMD_HEADER_LEN 4
 #define P4IO_MAX_PAYLOAD 60
 
@@ -37,7 +42,7 @@ struct p4io_cmd_package {
 };
 
 struct p4io_req_read_roundplug {
-    /* 0 = black, 1 = white */
+    // see enum p4io_roundplug_type
     uint8_t type;
 };