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/arch/arm/mach-k3/sysfw-loader.c b/arch/arm/mach-k3/sysfw-loader.c
index 4f5c848..6d54b65 100644
--- a/arch/arm/mach-k3/sysfw-loader.c
+++ b/arch/arm/mach-k3/sysfw-loader.c
@@ -10,6 +10,7 @@
 #include <spl.h>
 #include <malloc.h>
 #include <remoteproc.h>
+#include <asm/cache.h>
 #include <linux/soc/ti/ti_sci_protocol.h>
 #include <g_dnl.h>
 #include <usb.h>