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/board/phytec/pcm051/board.c b/board/phytec/pcm051/board.c
index 43f6c5a..e561c82 100644
--- a/board/phytec/pcm051/board.c
+++ b/board/phytec/pcm051/board.c
@@ -11,6 +11,7 @@
 #include <common.h>
 #include <env.h>
 #include <errno.h>
+#include <net.h>
 #include <spl.h>
 #include <asm/arch/cpu.h>
 #include <asm/arch/hardware.h>
diff --git a/board/phytec/pcm058/pcm058.c b/board/phytec/pcm058/pcm058.c
index 820b5fd..b1bf8d5 100644
--- a/board/phytec/pcm058/pcm058.c
+++ b/board/phytec/pcm058/pcm058.c
@@ -11,6 +11,7 @@
  */
 #include <common.h>
 #include <init.h>
+#include <net.h>
 #include <asm/io.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/imx-regs.h>
diff --git a/board/phytec/pfla02/pfla02.c b/board/phytec/pfla02/pfla02.c
index a3af823..7439aa5 100644
--- a/board/phytec/pfla02/pfla02.c
+++ b/board/phytec/pfla02/pfla02.c
@@ -6,6 +6,7 @@
 #include <common.h>
 #include <cpu_func.h>
 #include <init.h>
+#include <net.h>
 #include <asm/io.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/imx-regs.h>
diff --git a/board/phytec/phycore_rk3288/phycore-rk3288.c b/board/phytec/phycore_rk3288/phycore-rk3288.c
index 039ed0f..236342c 100644
--- a/board/phytec/phycore_rk3288/phycore-rk3288.c
+++ b/board/phytec/phycore_rk3288/phycore-rk3288.c
@@ -6,6 +6,7 @@
 
 #include <eeprom.h>
 #include <init.h>
+#include <net.h>
 #include <asm/io.h>
 #include <common.h>
 #include <dm.h>