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/drivers/net/fm/tgec.c b/drivers/net/fm/tgec.c
index 5017123..8d4622f 100644
--- a/drivers/net/fm/tgec.c
+++ b/drivers/net/fm/tgec.c
@@ -12,7 +12,7 @@
 #include <phy.h>
 #include <asm/types.h>
 #include <asm/io.h>
-#include <asm/fsl_tgec.h>
+#include <fsl_tgec.h>
 
 #include "fm.h"