common: Drop net.h from common header

Move this header out of the common header. Network support is used in
quite a few places but it still does not warrant blanket inclusion.

Note that this net.h header itself has quite a lot in it. It could be
split into the driver-mode support, functions, structures, checksumming,
etc.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/fat.c b/cmd/fat.c
index abce2f1..28fca50 100644
--- a/cmd/fat.c
+++ b/cmd/fat.c
@@ -11,6 +11,7 @@
 #include <mapmem.h>
 #include <fat.h>
 #include <fs.h>
+#include <asm/cache.h>
 
 int do_fat_size(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {