net: cosmetic: Clean up CDP variables and functions

Make a thorough pass through all variables and function names contained
within cdp.c and remove CamelCase and improve naming.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/net/net.c b/net/net.c
index a159432..3c8b608 100644
--- a/net/net.c
+++ b/net/net.c
@@ -412,7 +412,7 @@
 #endif
 #if defined(CONFIG_CMD_CDP)
 		case CDP:
-			CDPStart();
+			cdp_start();
 			break;
 #endif
 #if defined (CONFIG_NETCONSOLE) && !(CONFIG_SPL_BUILD)