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/cpu/armv7/ls102xa/cpu.c b/arch/arm/cpu/armv7/ls102xa/cpu.c
index 664c9c1..c544f38 100644
--- a/arch/arm/cpu/armv7/ls102xa/cpu.c
+++ b/arch/arm/cpu/armv7/ls102xa/cpu.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <cpu_func.h>
+#include <net.h>
 #include <vsprintf.h>
 #include <asm/arch/clock.h>
 #include <asm/io.h>
diff --git a/arch/arm/cpu/armv7/ls102xa/fdt.c b/arch/arm/cpu/armv7/ls102xa/fdt.c
index 16ab867..56ca7b0 100644
--- a/arch/arm/cpu/armv7/ls102xa/fdt.c
+++ b/arch/arm/cpu/armv7/ls102xa/fdt.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <clock_legacy.h>
+#include <net.h>
 #include <linux/libfdt.h>
 #include <fdt_support.h>
 #include <asm/io.h>