net: Move some header files to include/

The fsl_dtsec.h & fsl_tgec.h & fsl_fman.h can be shared on both ARM
and PPC, move it out of ppc to include/, and change the path in
drivers accordingly.

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: Gong Qianyu <Qianyu.Gong@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/board/freescale/t208xrdb/eth_t208xrdb.c b/board/freescale/t208xrdb/eth_t208xrdb.c
index cbbc625..ea51195 100644
--- a/board/freescale/t208xrdb/eth_t208xrdb.c
+++ b/board/freescale/t208xrdb/eth_t208xrdb.c
@@ -21,7 +21,7 @@
 #include <fsl_mdio.h>
 #include <miiphy.h>
 #include <phy.h>
-#include <asm/fsl_dtsec.h>
+#include <fsl_dtsec.h>
 #include <asm/fsl_serdes.h>
 
 int board_eth_init(bd_t *bis)